n. In architecture, the ornamental termination or apex of a pinnacle, canopy, gable, or the like, consisting usually of a knob or composition of foliage. By older writers the word is used to denote not only the termination, but the whole pyramidal mass.n. In decorative art, by extension from architecture, the ornamental termination, usually a knob, cluster of leaves, or the like, of any upward-pointing part.