tam vs tam-o'-shanter

tam and tam-o'-shanter both are nouns.

Word	Noun	Adjective	Verb	Adverb
tam	Yes	No	No	No
tam-o'-shanter	Yes	No	No	No

As nouns, tam and tam-o'-shanter are synonyms defined as:

Other synonyms of tam include tammy.

tam (noun)	tam-o'-shanter (noun)
a woolen cap of Scottish origin	a woolen cap of Scottish origin