derive: [14] Like rival, derive comes ultimately from Latin rīvus ‘stream’. This was used as the basis of a verb dērīvāre, formed with the prefix dē- ‘away’, which originally designated literally the ‘drawing off of water from a source’. This sense was subsequently generalized to ‘divert’, and extended figuratively to ‘derive’ (a metaphor reminiscent of spring from). English acquired the word via Old French deriver. => rival
