As a noun fivepence
is a monetary amount of five pence.
As an adjective fivepenny is
costing fivepence.
fivepence
English
Noun
(
en noun)
A monetary amount of five pence.
A coin of this value.
fivepenny
English
Adjective
(-)
(dated) Costing fivepence.
* This is a rare fivepenny stamp.