PIE *rueb,*reupから、捕らえる、奪う、語源的にはrape, rip, rupture。
Lord, hou schulde God approve tat tou robbe Petur, and gif tis robbere to Poule in te name of Crist? [Wyclif, c. 1380]To rob the cradle is attested from 1864 in reference to drafting young men in the American Civil War; by 1949 in reference to seductions or romantic relationships with younger persons. Related: Robbed; robbing.