As a noun insincerity
is property of being insincere, lacking sincerity or truthfulness.
As an adjective dishonest is
Property of being insincere, lacking sincerity or truthfulness.
- His insincerity was obvious to all; he was neither honest nor believable.
Interfering with honesty.
(obsolete) Dishonourable; shameful; indecent; unchaste; lewd.
* Alexander Pope
* Sir T. North
- inglorious triumphs and dishonest scars
(obsolete) Dishonoured; disgraced; disfigured.
- Speak no foul or dishonest words before them [the women].
- Dishonest with lopped arms the youth appears, / Spoiled of his nose and shortened of his ears.