shirker vs slacker

shirker and slacker both are nouns.

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

As nouns, shirker and slacker are synonyms defined as:

shirker and slacker: a person who shirks his work or duty (especially one who tries to evade military service in wartime)

shirker (noun)	slacker (noun)
a person who shirks his work or duty (especially one who tries to evade military service in wartime)	a person who shirks his work or duty (especially one who tries to evade military service in wartime)