This is the 7607th most frequent Chinese word.
起飞
"To take off" (used for aircraft).
In this sentence, "起飞" refers to a plane beginning its flight or becoming airborne.
飞机即将起飞，请系好安全带。
The airplane is about to take off; please fasten your seatbelt.
Here, "起飞" is used metaphorically to describe rapidly beginning success or growth.
他的事业在短时间内起飞，取得了巨大的成功。
His career took off in a short time, achieving great success.
In this usage, "起飞" again metaphorically signifies rapid improvement or advancement in a non-literal sense.