start vs begin

start is a noun but begin is not a noun.

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

As verbs, start and begin are synonyms defined as:

Other synonyms of start include commence, get, get down, set about, set out, start out.

As verbs, start and begin are synonyms defined as:

Other synonyms of start include commence, lead off.

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

Other hypernyms of start include commence, lead off, start.

As verbs, start and begin are synonyms defined as:

start and begin: begin an event that is implied and limited by the nature or inherent function of the direct object

As verbs, start and begin are synonyms defined as:

start and begin: have a beginning, in a temporal, spatial, or evaluative sense

As verbs, start and begin are synonyms defined as:

start (noun)	begin (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)	begin (verb)
take the first step or steps in carrying out an action	take the first step or steps in carrying out an action
set in motion, cause to start	set in motion, cause to start
play in the starting lineup	begin to speak or say
bring into being	begin to speak, understand, read, and write a language
get off the ground	achieve or accomplish in the least degree, usually used in the negative
begin or set in motion	begin an event that is implied and limited by the nature or inherent function of the direct object
get going or set in motion	have a beginning, in a temporal, spatial, or evaluative sense
depart for someplace	be the first item or point, constitute the beginning or start, come first in a series
bulge outward	have a beginning characterized in some specified way
move or jump suddenly, as if in surprise or alarm	have a beginning, of a temporal event
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