rubber stamp vs handstamp

rubber stamp and handstamp both are nouns.

Word	Noun	Adjective	Verb	Adverb
rubber stamp	Yes	No	No	No
handstamp	Yes	No	Yes	No

As nouns, rubber stamp and handstamp are synonyms defined as:

rubber stamp and handstamp: a stamp (usually made of rubber) for imprinting a mark or design by hand

rubber stamp (noun)	handstamp (noun)
routine authorization of an action without questions	a stamp (usually made of rubber) for imprinting a mark or design by hand
a stamp (usually made of rubber) for imprinting a mark or design by hand

rubber stamp (verb)	handstamp (verb)
	stamp with a rubber stamp, usually an indication of official approval on a document