Insincere /(?)/

In·sin·cere

Insincere

a.
  1. Not being in truth what one appears to be; not sincere; dissembling; hypocritical; disingenuous; deceitful; false; -- said of persons; also of speech, thought; etc.; as, insincere declarations.
  2. Disappointing; imperfect; unsound. [Obs.]
    To render sleep's soft blessings insincere.