twopenny-halfpenny vs twopenny

twopenny-halfpenny and twopenny both are adjectives.

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

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

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

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