set off vs start

set off is not a noun while start is a noun.

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

As verbs, start is a hypernym of set off; that is, start is a word with a broader meaning than set off:

Other hypernyms of set off include begin, commence, lead off.

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

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

set off (noun)	start (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

set off (verb)	start (verb)
cause to burst with a violent release of energy	take the first step or steps in carrying out an action
set in motion or cause to begin	set in motion, cause to start
direct attention to, as if by means of contrast	play in the starting lineup
provoke or stir up	bring into being
put in motion or move to act	get off the ground
depart for someplace	begin or set in motion
make up for	get going or set in motion
	depart for someplace
	bulge outward
	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