Webster's Revised Unabridged Dictionary · 1913

Simper

Simper , intransitive verb

[Compare Norw. semper fine, smart, dial. Danish semper, simper, affected, coy, prudish, OSw. semper one who affectedly refrains from eating, Swedish sipp finical, prim, LG. sipp.]

1.
To smile in a silly, affected, or conceited manner.
Behold yond simpering dame. — Shakespeare
With a made countenance about her mouth, between simpering and smiling. — ir. P. Sidney
2.
To glimmer; to twinkle. [Obsolete]
Yet can I mark how stars above Simper and shine. — Herbert

Simper , noun

A constrained, self-conscious smile; an affected, silly smile; a smirk.
The conscious simper, and the jealous leer. — Pope