sneak vs sneak out

sneak is a noun but sneak out is not a noun.

Word	Noun	Adjective	Verb	Adverb
sneak	Yes	Yes	Yes	No
sneak out	No	No	Yes	No

sneak (noun)	sneak out (noun)
someone acting as an informer or decoy for the police
someone who prowls or sneaks about; usually with unlawful intentions
a person who is regarded as underhanded and furtive and contemptible

sneak (adjective)	sneak out (adjective)
marked by quiet and caution and secrecy; taking pains to avoid being observed

sneak (verb)	sneak out (verb)
to go stealthily or furtively	leave furtively and stealthily
make off with belongings of others
pass on stealthily
put, bring, or take in a secretive or furtive manner