snatcher vs thief

snatcher and thief both are nouns.

Word	Noun	Adjective	Verb	Adverb
snatcher	Yes	No	No	No
thief	Yes	No	No	No

As nouns, thief is a hypernym of snatcher; that is, thief is a word with a broader meaning than snatcher:

snatcher: a thief who grabs and runs
thief: a criminal who takes property belonging to someone else with the intention of keeping it or selling it

Other hypernyms of snatcher include stealer.

snatcher (noun)	thief (noun)
someone who unlawfully seizes and detains a victim (usually for ransom)	a criminal who takes property belonging to someone else with the intention of keeping it or selling it
a thief who grabs and runs