"turned toward the observer, frontal," 1650s, from Latin obversus "turned against, directed toward," past participle of obvertere "to turn toward or against," from ob "toward" (see ob-) + vertere "to turn" (from PIE root *wer- (2) "to turn, bend"). According to OED, not in common use until the end of the 18th century. The noun, in reference to coins, medals, etc. (opposite of reverse), is attested from 1650s. Related: Obversely.