Anglicized form of Carolus (see Charles), or of its feminine derivative Carola. It has never been common as a boy's name, and has become even less so since its growth in popularity as a girl's name. This seems to be of relatively recent origin (not being found much before the end of the 19th century). It probably originated as a short form of Caroline.
South German: 1. habitational name for someone from Reis or Reissen in Bavaria (see Reis 1). 2. occupational name from Middle High German reisære ‘warrior’, ‘traveler’. 3. South German: topographic name for someone who lived near a thicket (see Rieser 1 and Riser 1). 4. variant spelling of Reisser, an occupational name for a woodcutter, Middle High German rīsser.