According to dictionary means a woody perennial plant, typically having a single stem or trunk growing to a considerable height and bearing lateral branches at some distance from the ground. Interestingly various trees are mentioned in Quran and Sunnah.
Allah says (interpretation of the meaning): "See you not how Allah sets forth a parable? – A goodly word is as a goodly tree, whose root is firmly fixed, and its branches (reach) to the sky (i.e., very high)." Quran Surah Ibrahim 14:24 
Narrated Anas bin Malik(R):Allah's Messenger (ﷺ) said, "There is none amongst the Muslims who plants a tree or sows seeds, and then a bird, or a person or an animal eats from it, but is regarded as a charitable gift for him." Sahih al-Bukhari 2320 (Vol.3: 513) and Sahih Muslim 1553
Narrated Abu Huraira(R):Allah's Messenger (ﷺ) said, "The example of a believer is that of a fresh green plant the leaves of which move in whatever direction the wind forces them to move and when the wind becomes still, it stand straight. Such is the similitude of the believer: He is disturbed by calamities (but is like the fresh plant he regains his normal state soon). And the example of a disbeliever is that of a pine tree (which remains) hard and straight till Allah cuts it down when He will." (See Hadith No. 546 and 547, Vol. 7). Sahih al-Bukhari 7466 (Vol. 9, Book 93, Hadith 558)
Narrated Ka`b:The Prophet (ﷺ) said, "The example of a believer is that of a fresh tender plant, which the wind bends lt sometimes and some other time it makes it straight. And the example of a hypocrite is that of a pine tree which keeps straight till once it is uprooted suddenly. Sahih al-Bukhari 5643 (Vol. 7, Book 70, Hadith 546) 
This is the tree to which Allah likens the believer because it is good in all aspects, it is lasting and it offers different kinds of benefit. Ibn ‘Umar reported: "The Prophet ﷺsaid: ‘There is a kind of tree whose leaves do not fall and it is like the Muslim. Tell me what it is.’ The people mentioned different kinds of desert trees … and I said to myself, ‘It is the date palm tree,’ but I felt too shy to speak up. Then the people said, ‘Tell us what it is, O Messenger of Allah.’ He said: ‘It is the date palm tree.’" Sahih al-Bukhari Vol1: 72
Allah says:And it is He who sends down rain from the sky, and We produce thereby the growth of all things. We produce from it greenery from which We produce grains arranged in layers. And from the palm trees - of its emerging fruit are clusters hanging low. And [We produce] gardens of grapevines and olives and pomegranates, similar yet varied. Look at [each of] its fruit when it yields and [at] its ripening. Indeed in that are signs for a people who believe. Quran Surah Anam 6:99
Allah is taking oath of Olive in Quran: And olive and palm trees Quran Surah Abasa 80.29:. By the fig and the olive Quran Surah 95.1
In Surat al-Mu’minun, Allah says (interpretation of the meaning): "And a tree (olive) that springs forth from Mount Sinai, that grows oil, and (it is a) relish for the eaters." Quran Surahal-Mu’minun 23:20
The tree which Allah caused to grow for Yunus (upon whom be peace) for food and healing. Allah says (interpretation of the meaning): "And, verily, Yunus was one of the Messengers … Then a (big) fish swallowed him and he had done an act worthy of blame. Had he not been of those who glorify Allah, he would have indeed remained inside its belly until the Day of Resurrection. But We cast him forth on the naked shore while he was sick, and We caused a plant of gourd to grow over him." Quran Surahal-Saffat 37:139, 142-146
The Mufassirin (commentators) said: The gourd (al-Yaqtin) is a kind of pumpkin. Some of them described the benefits of the pumpkin, such as: it grows quickly, it provides shade, it has large, smooth leaves, it keeps flies away and its fruit provides good nourishment: it can be eaten raw or cooked, and its skin may be eaten too. It is known that the Messenger of Allah ﷺliked this kind of pumpkin and used to look for it on the plate of food. (Tafsir Ibn Kathir).
Allah says (interpretation of the meaning): "And indeed he (Muhammad ﷺsaw him (Jibril) at a second descent (i.e., another time), near Sidrat al-Muntaha (the lote tree of the utmost boundary, beyond which none can pass), near it is the Paradise of Abode, when that covered the lote-tree which did cover it! The sight (of Prophet Muhammad ﷺ) turned not aside (right or left), nor did it transgress beyond (the) limit (ordained for it). Indeed, he did see of the Greatest Signs of his Lord (Allah)." Quran Surahal-Najm 53:13-18
The phrase translated here as "when that covered the lote-tree which did cover it" is explained by the Hadith narrated by Imam al-Bukhari from Abu Dharr, in which the Prophet ﷺsaid: "It was covered in colors, I do not know what they are…" According to a Hadith narrated by Abu Sa’id and Ibn ‘Abbas, he said: "It was covered by the angels." According to a report narrated by Muslim, he said: "When it was covered with whatever covered it by the command of Allah, it changed, and none of the creation of Allah could describe its beauty."
The reason why it is called Sidrat al-Muntaha is stated in the Hadith narrated from Ibn Mas’ud by Imam Muslim: "There everything that comes up from earth stops (Yantahi), and it is taken from there, and there everything that comes down stops, and it is taken from there." Al-Nawawi said: It is called Sidrat al-Muntaha because the knowledge of the angels stops at that point, and no one has gone beyond it except the Messenger of Allah ﷺ.
Narrated Abu Huraira(R): The Prophet (ﷺ) said "There is a tree in Paradise (which is so big and huge that) a rider could travel in its shade for a hundred years. And if you wish, you can recite:--'In shade long extended..' (56. 30) and a place in Paradise equal to an arrow bow of one of you, is better than (the whole earth) on which the sun rises and sets." Sahih al-Bukhari 3252, 3253 (Vol. 4, Book 54, Hadith 475)
The tree of Zaqqum, which is the food of the people of Hell. This tree is described in the Quran as (interpretation of the meaning): "… the accursed tree (mentioned) in the Quran" Quran Surahal-Isra’ 17:60
Allah also says about it (interpretation of the meaning): "Then, moreover, verily, - you the erring-ones, the deniers (of Resurrection)! You verily will eat of the trees of Zaqqum. Then you will fill your bellies therewith, and drink boiling water on top of it, so you will drink (that) like thirsty camels! That will be their entertainment on the Day of Recompense!" Quran Surahal-Waqi’ah 56:51-56
"Is that (Paradise) better entertainment or the tree of Zaqqum (a horrible tree in Hell)? Truly We have made it (as) a trial for the Dhalimin (polytheists, disbelievers, wrongdoers, etc.). Verily, it is a tree that springs out of the bottom of Hell-fire, the shoots of its fruit-stalks are like the heads of Shayatin (devils); truly they will eat thereof and fill their bellies therewith. Then on the top of that they will be given boiling water to drink so that it becomes a mixture (of boiling water and Zaqqum in their bellies). Then, thereafter, their return is to the flaming fire of Hell." Quran Surahal-Saffat 37:62-68
The tree under which the Prophet ﷺaccepted his Companions’ pledge of allegiance unto death and not to desert him
This happened during the campaign of al-Hudaybiyah, when he heard of the betrayal of the Mushrikin. This tree is also mentioned in the Quran (interpretation of the meaning):Certainly was Allah pleased with the believers when they pledged allegiance to you, [O Muhammad], under the tree, and He knew what was in their hearts, so He sent down tranquillity upon them and rewarded them with an imminent conquest
Narrated Jabir bin `Abdullah:The Prophet (ﷺ) used to stand by a tree or a date-palm on Friday. Then an Ansari woman or man said. "O Allah's Messenger (ﷺ)! Shall we make a pulpit for you?" He replied, "If you wish." So they made a pulpit for him and when it was Friday, he proceeded towards the pulpit (for delivering the sermon). The datepalm cried like a child! The Prophet (ﷺ) descended (the pulpit) and embraced it while it continued moaning like a child being quietened. The Prophet (ﷺ) said, "It was crying for (missing) what it used to hear of religious knowledge given near to it." Sahih al-Bukhari 3584 (Vol. 4, Book 56, Hadith 784)
Allah says in the Quran: But when he came to it, he was called from the right side of the valley in a blessed spot - from the tree, "O Moses, indeed I am Allah , Lord of the worlds." Quran Surah al-Qasas 28:30
Allah says (interpretation of the meaning): "And O Adam! Dwell you and your wife in Paradise, and eat thereof as you both wish, but approach not this tree, otherwise you both will be of the Dhalimin (unjust and wrong-doers)." Quran Surah al-A’raf 7:19
This was recorded in the Sahih report narrated by Imam Muslim, may Allah have mercy on him, from Jabir (may Allah be pleased with him): "… We stopped in a spaciousvalley, and Allah's Messenger (ﷺ) went to relieve himself. I followed him with a bucket full of water and Allah's Messenger (ﷺ) looked about and he found no privacy but two trees at the end of the valley and Allah's Messenger (may. peace be upon him) went to one of them and took hold of one of its twigs and said: ‘Follow me, by the permission of Allah.’ So it followed him like a camel being led by a rope, until he came to the other tree. He took one of the other tree’s branches and said: ‘Follow me, by the permission of Allah.’ So it followed him until he reached the halfway point between them, then he put them together and said: ‘Stay together and cover me, by the permission of Allah.’ So they stayed together." Jabir said: "I kept away, for fear that the Messenger of Allah ﷺmight feel my presence and move even further away. So I sat down, thinking to myself, and when I turned around, I saw the Messenger of Allah ﷺcoming towards me, and the two trees had separated and taken up their former positions." Sahih Muslim, 3012