ascent vs takeoff

ascent and takeoff both are nouns.

Word	Noun	Adjective	Verb	Adverb
ascent	Yes	No	No	No
takeoff	Yes	No	No	No

As nouns, takeoff is a hyponym of ascent; that is, takeoff is a word with a more specific, narrower meaning than ascent:

ascent (noun)	takeoff (noun)
the act of changing location in an upward direction	a departure; especially of airplanes
a movement upward; rise above the ground	humorous or satirical mimicry
an upward slope or grade (as in a road)	a composition that imitates or misrepresents somebody's style, usually in a humorous way
	the initial ascent of an airplane as it becomes airborne