The Collaborative International Dictionary of English v.0.48:

Potboy \Pot"boy`\, n.
   A boy who carries pots of ale, beer, etc.; a menial in a
   public house.
   [1913 Webster]

WordNet (r) 3.0 (2006):

potboy
    n 1: a worker in an inn or public house who serves customers and
         does various chores [syn: potboy, potman]