sneak vs pilfer

sneak is a noun but pilfer is not a noun.

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

As verbs, sneak and pilfer are synonyms defined as:

Other synonyms of sneak include abstract, cabbage, filch, hook, lift, nobble, pinch, purloin, snarf, swipe.

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

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