Makrooh is an Arabic word which means the opposite of liked or loved. In the terminology of sharee’ah it means that which the Lawgiver asks us not to do, but not in a definitive manner. It may be said that it means that for which the person who does not do it out of obedience will be rewarded, but the one who does it will not be punished. 
This hadeeth has supporting evidence , Abu Hurayrah (may Allaah be pleased with him), that the Prophet (peace and blessings of Allaah be upon him) said: “Do not pluck out grey hairs, for they will be light on the Day of Resurrection. If a man’s hair turns grey in Islam, for each grey hair he will have one hasanah and will rise one degree in status.” Narrated by Ibn Hibbaan. Al-Albaani said in Silsilat al-Ahaadeeth al-Saheehah (3/247): its isnaad is hasan.
It is also narrated from ‘Amr ibn ‘Absah (may Allaah be pleased with him) that the Messenger of Allaah (peace and blessings of Allaah be upon him) said: “If a person’s hair turns grey for the sake of Allaah, it will be light for him on the Day of Resurrection.” Classed as saheeh by al-Albaani in Saheeh al-Tirmidhi 1635 
In brief, the times are:
Ibn ‘Abbaas, who said: Some trustworthy men bore witness in my presence, the most trustworthy of whom in my view was ‘Umar, that the Prophet (peace and blessings of Allaah be upon him) forbade praying after Fajr until the sun had risen and after ‘Asr until the sun had set.” This is indicated by the report narrated by Sahih Al Bukhari 547 and Sahih Muslim 1367
Abu Sa’eed al-Khudri said: I heard the Messenger of Allaah (peace and blessings of Allaah be upon him) say: “There is no prayer after Fajr until the sun has risen fully, and no prayer after ‘Asr until the sun has set.” Sahih Al Bukhari 551
Uqbah ibn ‘Aamir al-Juhani said: “There are three times at which the Messenger of Allaah (peace and blessings of Allaah be upon him) forbade us to pray or to bury our dead: when the sun has clearly started to rise until it is fully risen, when it is directly overhead at midday until it has passed its zenith, and when the sun starts to set until it has fully set.” Sahih Muslim 1373  
It is makrooh to speak after ‘Isha’ prayer unless that is for a reason, or speaking about some good topic, because it was narrated in al-Saheehayn from Abi Barzah that the Messenger of Allaah (peace and blessings of Allaah be upon him) used to dislike sleeping before ‘Isha’ and speaking afterwards. Sahih al Bukhaari, 568 and Muslim, 647
Abu Moosa al-Ash’ari that the Messenger of Allaah (peace and blessings of Allaah be upon him) delayed the prayer until it was nearly midnight, then the Messenger of Allaah (peace and blessings of Allaah be upon him) went out and led them in prayer. When he finished his prayer he said to those who were with him: “Wait a moment. Receive the glad tidings that by the blessing of Allaah to you, no one has prayed at this hour except you.” Sahih al-Bukhari 567
Al-Nawawi (may Allaah have mercy on him) said in his commentary:
The scholars said: The reason for it being makrooh to sleep beforehand is that one risks missing the prayer by sleeping too deeply, or one risks missing the preferred and best time for the prayer, and lest the people take this matter lightly and sleep and miss the prayer in congregation.