Pl. trochi, also trochuses. [L., a. Gr. τροχός, f. τρέχειν to run.]
1. Gr. and Rom. Antiq. A wheel or hoop, used in athletic exercises or as a plaything.
1706. Phillips (ed. Kersey), Trochus, a Wheel, a Top for Children to play with.
1734. trans. Rollin’s Anc. Hist. (1768), I. Pref. 88. The exercises of leaping, throwing the dart, and that of the trochus or wheel.
1847. Leitch, trans. C. O. Müller’s Anc. Art, § 351 (1850), 427. Ganymede with trochus.
† 2. = TROCHE2. Obs. rare–1.
1748. trans. Vegetius’ Distemp. Horses, 85. Three Trochus’s or Cakes of Sinoper.
3. Zool. a. A genus of gastropod mollusks, having a top-shaped or conical shell; the type of the family Trochidæ or top-shells.
1753. Chambers, Cycl. Supp., Trochus,… a genus of shells.
1774. Goldsm., Nat. Hist. (1776), VII. 33. The trunk of the Trochus is fleshy, muscular, supple, and hollow.
1851. Woodward, Mollusca (1856), 12. The trochi and purpuræ are found at low-water, amongst the sea-weed.
1859. H. Kingsley, G. Hamlyn, xxxiv. (1894), 325. They fell to gathering shells…. Trochuses, as big as one’s fist.
attrib. and Comb. 1774. Goldsm., Nat. Hist., IV. 22. Snails of the trochus kind.
1889. Science-Gossip, XXV. 168. Trochus-shaped rotulites.
b. The internal ring of cilia in the trochal organ of a rotifer.
1888. Rolleston & Jackson, Anim. Life, 632. The trochal apparatus appears to consist typically of an internal præoral ring of long cilia, the trochus, and an external ring of finer cilia, the cingulum.
