a. and sb. Math. [ad. L. ēvolvent-em, pr. pple. f. ēvolvĕre: see EVOLVE.]
A. adj. That evolves. † Evolvent line: the right line (the tangent to the evolute), the extremity of which is the locus of the involute. B. sb. 1. The involute of a curve. 2. (See quot. 1862.)
1708. trans. Gregory’s Prop. Catenaria, in Misc. Cur., II. 236. The Evoluent Line UF is a third Proportional to AC and CB.
1727–51. Chambers, Cycl., Evolvent, in geometry … the curve resulting from the evolution of a curve; in contradistinction to the evolute.
1796. in Hutton, Math. Dict.
1862. F. Hall, Hindu Philos. Syst., Pref. p ix. note. ‘Originant’ might answer, or ‘evolvent’ [for prakṛiti]; and ‘originate’ or ‘evolute’ for vikṛiti.
1882. E. B. Cowell, in trans. Sarva-darśana-saṃgraha, 221. That which is evolvent only [note, I borrow this term from Dr. Hall.].
