costate

Etymology 1
Borrowed from.

Adjective

 * 1) Having ribs, or the appearance of ribs.
 * 2)  Having one or more longitudinal ribs.

Derived terms

 * homocostate

Noun

 * 1)  A state in alliance with another state.
 * 2)  An equation or variable related to the state equation of an optimal control problem in a dynamical system.