twopenny vs twopenny-halfpenny

twopenny and twopenny-halfpenny both are adjectives.

Word	Noun	Adjective	Verb	Adverb
twopenny	No	Yes	No	No
twopenny-halfpenny	No	Yes	No	No

As adjectives, twopenny and twopenny-halfpenny are synonyms defined as:

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

twopenny (adjective)	twopenny-halfpenny (adjective)
of trifling worth	of trifling worth