Webster's Revised Unabridged Dictionary · 1913

Instar

Instar , transitive verb

To stud as with stars. [Rare]
A golden throne instarred with gems. — J. Barlow

Instar , noun

a postembryonic stage of life of an arthropod, especially an insect, between two successive molts; also, the arthropod when in that stage of life.