Noah Webster's New International Dictionary of the English Language

1. (n.) A tuft, or other excrescence or natural ornament, growing on an animal's head; the comb of a cock; the swelling on the head of a serpent; the lengthened feathers of the crown or nape of bird, etc.

2. (n.) The plume of feathers, or other decoration, worn on a helmet; the distinctive ornament of a helmet, indicating the rank of the wearer; hence, also, the helmet.

3. (n.) A bearing worn, not upon the shield, but usually above it, or separately as an ornament for plate, liveries, and the like. It is a relic of the ancient cognizance. See Cognizance.

4. (n.) The upper curve of a horse's neck.

5. (n.) The ridge or top of a wave.

6. (n.) The summit of a hill or mountain ridge.

7. (n.) The helm or head, as typical of a high spirit; pride; courage.

8. (n.) The ornamental finishing which surmounts the ridge of a roof, canopy, etc.

9. (n.) The top line of a slope or embankment.

10. (v. t.) To furnish with, or surmount as, a crest; to serve as a crest for.

11. (v. t.) To mark with lines or streaks, like, or regarded as like, waving plumes.

12. (v. i.) To form a crest.