threepenny vs twopenny

threepenny and twopenny both are adjectives.

Word	Noun	Adjective	Verb	Adverb
threepenny	No	Yes	No	No
twopenny	No	Yes	No	No

As adjectives, threepenny and twopenny are synonyms defined as:

Other synonyms of threepenny include sixpenny, tuppeny, two-a-penny, twopenny-halfpenny.

threepenny (adjective)	twopenny (adjective)
of trifling worth	of trifling worth
used of nail size; 1 1/4 in long