A tuft, or other natural ornament, growing on an animal's head, for example the comb of a cockerel, the swelling on the head of a snake, the lengthened feathers of the crown or nape of bird, etc.
The plume of feathers, or other decoration, worn on or displayed on a helmet; the distinctive ornament of a helmet.
A bearing worn, not upon the shield, but usually on a helmet above it, sometimes (as for clerics) separately above the shield or separately as a mark for plate, in letterheads, and the like.