Isorropic

I′sor‐rop″ic (?), a. [Gr. ισὄρροποσ in equipoise; ἴσοσ equal + ροπἥ downward inclination or momentum.] Of equal value.

Isorropic line (in a diagram) (Geom.), the locus of all the points for which a specified function has a constant value. Newcomb.