start vs commencement

start and commencement both are nouns.

Word	Noun	Adjective	Verb	Adverb
start	Yes	No	Yes	No
commencement	Yes	No	No	No

As nouns, start and commencement are synonyms defined as:

Other synonyms of start include beginning.

As nouns, start and commencement are synonyms defined as:

start and commencement: the time at which something is supposed to begin

Other synonyms of start include beginning, first, get-go, kickoff, offset, outset, showtime, starting time.

start (noun)	commencement (noun)
the act of starting something	the act of starting something
a sudden involuntary movement	an academic exercise in which diplomas are conferred
a turn to be a starter (in a game at the beginning)	the time at which something is supposed to begin
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)	commencement (verb)
take the first step or steps in carrying out an action
set in motion, cause to start
play in the starting lineup
bring into being
get off the ground
begin or set in motion
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