shirker vs shammer

shirker and shammer both are nouns.

Word	Noun	Adjective	Verb	Adverb
shirker	Yes	No	No	No
shammer	Yes	No	No	No

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

shirker: a person who shirks his work or duty (especially one who tries to evade military service in wartime)
shammer: someone shirking their duty by feigning illness or incapacity

Other hyponyms of shirker include goldbrick, malingerer, skulker, scrimshanker.

shirker (noun)	shammer (noun)
a person who shirks his work or duty (especially one who tries to evade military service in wartime)	a person who makes deceitful pretenses
	someone shirking their duty by feigning illness or incapacity