evolute

 
Pronunciation: /ˈiːvəl(j)uːt, ˈɛv-/

noun

(also evolute curve) Mathematics
  • a curve which is the locus of the centres of curvature of another curve (its involute).

adjective

Zoology & Botany
  • rolled outwards at the edges: an evolute shell

Origin:

mid 18th century: from Latin evolutus, past participle of evolvere 'roll out' (see evolve)