Definition of: header

(hed′ər) noun
1. A person who makes or puts on heads, as in barrelmaking.
2. Colloq. A plunge or fall headforemost, as diving.
3. One of various machines or tools for making, attaching, or removing heads; especially, a kind of harvesting machine that cuts the ripe heads off grain in the field.
4. A brick or stone placed with its end toward the face of a wall.
5. In building, a timber resting in trimmers and carrying the ends or heads of the tail beams.
6. A pipe, duct, channel, or conduit which serves as a central distributing point of a fluid flow to auxiliary branches.