To shiver with cold, as a hawk or other bird.n. A shivering with cold, as a bird; the ruffling of a bird's feathers when shivering with cold.n. A narrow ornamental bordering made of a strip of textile material, of which one edge is gathered and the other left loose, as in a narrow flounce; a ruffle.n. Hence Anything resembling such a border.n. Specificallyn. The projecting fringe of hair on the chest of some dogs, as the collie.n. Some fringing part or process of an animal, like a ruffle; a frilling: as, the genital frills of a hydrozoan.n. In hymenomycetous fungi, a superior annulus or ring; an annulus formed of tissue suspended from the apex of the stipe and free at other points, at first forming a membranous covering for the hymenium, but detached as the pileus expands; an armilla.n. In photography, the swelling and loosening of a gelatin film around the edges of a plate. See frill, verbn. An affectation of dress or of manner; an air: usually in the plural: as, he puts on too many frills.To form into a frill; flute or plait: as, to frill a border in a dress.To ornament with frills; as, to frill a child's garment.To become frilled or ruffled.n. The shell of a kind of scallop.