(zoology) The whole top of the head of a bird from the base of the bill to the nape of the neck.
(architecture) The uppermost of any assemblage of parts.
Something covering the top or end of a thing for protection or ornament.
(nautical) A collar of iron or wood used in joining spars, as the mast and the topmast, the bowsprit and the jib boom; also, a covering of tarred canvas at the end of a rope.
(geometry) A portion of a spherical or other convex surface.