"Assentatory" is a word in ENGLISH

Insincere, flattering, or obsequious assent; hypocritical or pretended concurrence.

An obsequious; a flatterer.

Servilely or meanly attentive; compliant to excess; cringing; fawning; as, obsequious flatterer, parasite.

Bending to the humor of others; flattering; fawning; obsequious.

To play the sycophant toward; to flatter obsequiously.

Of or pertaining to a sycophant; characteristic of a sycophant; meanly or obsequiously flattering; courting favor by mean adulation; parasitic.

Like a sycophant; obsequiously flattering.

A fawning, obsequious parasite; a mean sycophant; a flatterer; a toady.