Noah Webster
Unsincere
UNSINCE'RE, adjective
1. Not sincere; hypocritical. [See Insincere.]
2. Not genuine; adulterated.
3. Not sound; not solid.
[Obsolete in the two last significations, and for the first, insincere is generally used.]
INSINCERITY, noun Insincerity; cheat. [Not used.] [See Insincerity.]