old salt vs tar

old salt and tar both are nouns.

Word	Noun	Adjective	Verb	Adverb
old salt	Yes	No	No	No
tar	Yes	No	Yes	No

As nouns, old salt and tar are synonyms defined as:

Other synonyms of old salt include gob, Jack-tar, Jack, mariner, sea dog, seafarer, seaman.

old salt (noun)	tar (noun)
a man who serves as a sailor	a man who serves as a sailor
	any of various dark heavy viscid substances obtained as a residue

old salt (verb)	tar (verb)
	coat with tar