start vs opening

start and opening both are nouns.

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

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

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

start (noun)	opening (noun)
the act of starting something	a recognized sequence of moves at the beginning of a game of chess
a sudden involuntary movement	the act of opening something
a turn to be a starter (in a game at the beginning)	becoming open or being made open
the advantage gained by beginning early (as in a race)	the first of a series of actions
a signal to begin (as in a race)	a vacant or unobstructed space that is man-made
the beginning of anything	an entrance equipped with a hatch; especially a passageway between decks of a ship
a line indicating the location of the start of a race or a game	an aperture or hole that opens into a bodily cavity
the time at which something is supposed to begin	a possible alternative
	the initial part of the introduction
	the first performance (as of a theatrical production)
	a ceremony accompanying the start of some enterprise
	an open or empty space in or between things
	opportunity especially for employment or promotion

start (adjective)	opening (adjective)
	first or beginning

start (verb)	opening (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