workman vs stamper

workman and stamper both are nouns.

Word	Noun	Adjective	Verb	Adverb
workman	Yes	No	No	No
stamper	Yes	No	No	No

As nouns, stamper is a hyponym of workman; that is, stamper is a word with a more specific, narrower meaning than workman:

workman: an employee who performs manual or industrial labor
stamper: a workman whose job is to form or cut out by applying a mold or die (either by hand or by operating a stamping machine)

workman (noun)	stamper (noun)
an employee who performs manual or industrial labor	a power tool that stamps
	someone who walks with a heavy noisy gait or who stamps on the ground
	a workman whose job is to form or cut out by applying a mold or die (either by hand or by operating a stamping machine)