insincere
in-sin-cere
adjective
Not expressing genuine feelings; pretending to feel something one does not.
"His insincere apology did not convince anyone."
Thesaurus
Synonyms: hypocritical, glossy, specious, gilded, oleaginous, feigned, obsequious, fulsome, fawning, plausible, toadyish, false
Antonyms: sincere