versed (adj.)

"practiced, conversant, acquainted," c. 1600, from past participle of obsolete verse "to turn over" (a book, subject, etc.) in study or investigation, from Middle French verser "to turn, revolve" as in meditation (12c.), from Latin versare "be employed, busy oneself," literally "to turn to, turn often; think over," frequentative of vertere "to turn," from PIE root *wer- (2) "to turn, bend."