the compound noun 'takeoff' is a modern formation from the phrasal verb 'to take off'. the verb 'take' originates from old english 'tacan', a borrowing from old norse 'taka', meaning to grasp or seize. 'off' derives from old english 'of', an adverb and preposition indicating separation or removal. the literal sense of an aircraft seizing itself away from the ground provides a clear, logical path to the modern meaning of departure or ascent. this concrete aviation term subsequently broadened metaphorically to describe a rapid departure or the beginning of a rapid increase, while the sense of a humorous imitation plays on the idea of 'lifting' mannerisms from someone.

Structure: take + off take (verb, from old english 'tacan', meaning to grasp or seize). off (adverb/preposition, from old english 'of', meaning away or from).