Meaning of barrelhead

bar•rel•head

Pronunciation: (bar'ul-hed"), [key]
— n.
  1. either of the round, flat sections that form the top and bottom of a barrel.
  2. in advance or on demand: They won't deliver the merchandise unless we pay cash on the barrelhead.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.