Header - definition of header by The Free Dictionary
head·er (hĕd′ər) n. 1. One that fits a head on an object. 2. One that removes a head from an object, especially a machine that reaps the heads of grain and passes them into a wagon or receptacle. 3. A pipe that serves as a central connection for two or more smaller pipes. 4. A floor or roof beam placed between two long beams that supports the ends ...