versus (prep.) Look up versus at Dictionary.com
mid-15c., in legal case names, denoting action of one party against another, from Latin versus "turned toward or against," from past participle of vertere (frequentative versare) "to turn, turn back, be turned; convert, transform, translate; be changed," from PIE *wert- "to turn, wind," from root *wer- (3) "to turn, bend" (source also of Old English -weard "toward," originally "turned toward," weorthan "to befall," wyrd "fate, destiny," literally "what befalls one;" Sanskrit vartate "turns round, rolls;" Avestan varet- "to turn;" Old Church Slavonic vrŭteti "to turn, roll," Russian vreteno "spindle, distaff;" Lithuanian ver čiu "to turn;" Greek rhatane "stirrer, ladle;" German werden, Old English weorðan "to become" (for sense, compare turn into); Welsh gwerthyd "spindle, distaff;" Old Irish frith "against").