plodder vs stick-in-the-mud

plodder and stick-in-the-mud both are nouns.

Word	Noun	Adjective	Verb	Adverb
plodder	Yes	No	No	No
stick-in-the-mud	Yes	Yes	No	No

As nouns, plodder and stick-in-the-mud are synonyms defined as:

Other synonyms of plodder include slowcoach, slowpoke.

plodder (noun)	stick-in-the-mud (noun)
someone who moves slowly	someone who moves slowly
someone who works slowly and monotonously for long hours
someone who walks in a laborious heavy-footed manner

plodder (adjective)	stick-in-the-mud (adjective)
	(used pejoratively) out of fashion; old fashioned