equivalent (adj.)

early 15c., from Middle French equivalent and directly from Late Latin aequivalentem (nominative aequivalens) "equivalent," present participle of aequivalere "be equivalent," from Latin aequus "equal" (see equal (adj.)) + valere "be well, be worth" (from PIE root *wal- "to be strong"). As a noun from c. 1500, "that which is equal or corresponds to." Related: Equivalently.