1911 Encyclopædia Britannica/Crest

CREST (Lat. crista, a plume or tuft), the “comb” on an animal’s head, and so any feathery tuft or excrescence, the “cone” of a helmet (by transference, the helmet itself), and the top or summit of anything. In heraldry (q.v.) a crest is a device, originally borne as a cognizance on a knight’s helmet, placed on a wreath above helmet and shield in armorial bearings, and used separately on a seal or on articles of property.

Cresting, in architecture, is an ornamental finish in the wall or ridge of a building, which is common on the continent of Europe. An example occurs at Exeter cathedral, the ridge of which is ornamented with a range of small fleurs-de-lis in lead.