start vs take off

start is a noun but take off is not a noun.

Word	Noun	Adjective	Verb	Adverb
start	Yes	No	Yes	No
take off	No	No	Yes	No

As verbs, take off is a hyponym of start; that is, take off is a word with a more specific, narrower meaning than start:

Other hyponyms of start include come on, come up, go on, get off the ground.

As verbs, start and take off are synonyms defined as:

Other synonyms of start include depart, part, set forth, set off, set out, start out.

As verbs, take off is a hyponym of start; that is, take off is a word with a more specific, narrower meaning than start:

Other hyponyms of start include lift off, roar off, blaze, blaze out, sally forth, sally out.

start (noun)	take off (noun)
the act of starting something
a sudden involuntary movement
a turn to be a starter (in a game at the beginning)
the advantage gained by beginning early (as in a race)
a signal to begin (as in a race)
the beginning of anything
a line indicating the location of the start of a race or a game
the time at which something is supposed to begin

start (verb)	take off (verb)
take the first step or steps in carrying out an action	remove clothes or shoes
set in motion, cause to start	take away
play in the starting lineup	make a subtraction
bring into being	prove fatal
get off the ground	mimic or imitate in an amusing or satirical manner
begin or set in motion	depart for someplace
get going or set in motion	get started or set in motion, used figuratively
depart for someplace	depart from the ground
bulge outward	take time off from work; stop working temporarily
move or jump suddenly, as if in surprise or alarm
begin work or acting in a certain capacity, office or job
begin an event that is implied and limited by the nature or inherent function of the direct object
have a beginning, in a temporal, spatial, or evaluative sense
have a beginning characterized in some specified way