We don't have synonyms for neopenis yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are neomenia, neotenic and reopens.
(n) :
A surgically constructed penis, as of a transgender man who has undergone sex reassignment surgery, or a cisgender man who lacked a penis due to a congenital defect, illness, or injury.
(n) :
A surgically constructed penis, as of a transgender man who has undergone sex reassignment surgery, or a cisgender man who lacked a penis due to a congenital defect, illness, or injury.