variable noun. Lift-off is the beginning of a rocket's flight into space, when it leaves the ground. The lift-off was delayed about seven minutes. The rocket tumbled out of control shortly after lift-off.

lift verb (TAKE HOLD) [ I or T, usually + adv/prep ] to take hold of and raise something in order to remove, carry, or move it to a different position: She lifted the baby out of her chair.

Synonyms: lift, raise, elevate, hoist, heave, boost. These verbs mean to move something from a lower to a higher level or position. Lift sometimes stresses the expenditure of effort: a trunk too heavy to lift. Raise often implies movement to an approximately vertical position: raised my hand so I could ask a question.

Begin flight, as in The spacecraft was due to lift off at ten o'clock. The off in this idiom means “off the ground.” [Late 1800s] The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company.