slacker vs shirker

slacker and shirker both are nouns.

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

As nouns, slacker and shirker are synonyms defined as:

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

slacker (noun)	shirker (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)