{v.} 1. To serve. * /Sue has a summer job waiting on an invalid./ * /The clerk in the store asked if we had been waited upon./ 2. {formal} To visit as a courtesy or for business. * /We waited upon the widow out of respect for her husband./ * /John waited upon the President with a letter of introduction./ 3. To follow. * /Success waits on hard work./
See: WAIT ON.