The Takbīr or Tekbir (تَكْبِير) is the Arabic term for the phrase Allāhu Akbar (الله أكبر). It is usually translated "God is [the] Greatest," or "God is Great". It is a common Islamic Arabic expression. It is used in various contexts by Muslims: in formal prayer, as an informal expression of faith, in times of distress, to express celebration or victory, and to express resolute determination or defiance (especially in politically charged contexts).

The form Allāhu is the nominative of Allah "God". The form akbar is the elative of the adjective kabīr "great", from the root k-b-r. As used in the takbir it is usually translated as "greatest", but some authors prefer "greater". The term takbīr itself is the stem II verbal noun (tafʿīlun) of the triliteral root k-b-r "great".

This phrase is recited by Muslims in many different situations. For example, when they are very happy, to express approval, to praise a speaker, or as a battle cry, during times of extreme stress. In the Islamic world, instead of applause, often someone will shout "takbir" and the crowd will respond "Allahu Akbar" in response.

Michael Gerard "Mike" Tyson (born June 30, 1966) is a retired American professional boxer. Tyson is a former undisputed heavyweight champion of the world and holds the record as the youngest boxer to win the WBC, WBA and IBF heavyweight titles at 20 years, 4 months and 22 days old. Tyson won his first 19 professional bouts by knockout, with 12 of them occurring in the first round. He won the WBC title in 1986 after defeating Trevor Berbick by a TKO in the second round. In 1987, Tyson added the WBA and IBF titles after defeating James Smith and Tony Tucker. He was the first heavyweight boxer to simultaneously hold the WBA, WBC and IBF titles, and the only heavyweight to individually unify them.

In 1988, Tyson became the lineal champion when he knocked out Michael Spinks in the first 91 seconds of the fight. Tyson successfully defended the world heavyweight championship nine times, including victories over Larry Holmes and Frank Bruno. Tyson lost his titles to 42-to-1 underdog James "Buster" Douglas on February 11, 1990, in Tokyo, Japan, by a knockout in round 10. Tyson continued in his quest to regain the titles, defeating Donovan Ruddock twice in 1991. Tyson was then scheduled to take on the undisputed heavyweight champion Evander Holyfield but pulled out due to injury.