circles (noun)
51french curve — noun Usage: often capitalized F : a curved piece of flat material (as wood, ebonite, celluloid) often in the form of a scroll and used as an aid in drawing noncircular curves * * * a flat drafting instrument, usually consisting of a sheet of… …
52ring spot — noun 1. : a lesion of plant tissue consisting of yellowish, purplish, or necrotic, often concentric rings 2. : any plant disease of which ring spots are the characteristic lesion: as a. : a virus disease of tobacco and related plants producing… …
53armillary sphere — noun Etymology: French sphère armillaire, from Medieval Latin armilla, from Latin, bracelet, iron ring, from armus shoulder more at arm Date: 1664 an old astronomical instrument composed of rings showing the positions of important circles of the… …
54cat's-eye — noun (plural cat s eyes) Date: circa 1599 1. any of various gems (as a chrysoberyl or a chalcedony) exhibiting opalescent reflections from within 2. a marble with eyelike concentric circles …
55ellipsoid — noun Date: 1721 a surface all plane sections of which are ellipses or circles • ellipsoidal also ellipsoid adjective …
56lune — noun Etymology: Latin luna moon more at lunar Date: circa 1704 the part of a plane surface bounded by two intersecting arcs or of a spherical surface bounded by two great circles …
57polygon — noun Etymology: Late Latin polygonum, from Greek polygōnon, from neuter of polygōnos polygonal, from poly + gōnia angle more at gon Date: 1571 1. a closed plane figure bounded by straight lines 2. a closed figure on a sphere bounded by arcs of… …
58rosette — noun Etymology: French, literally, small rose, from Old French, from rose, from Latin rosa Date: 1790 1. an ornament usually made of material gathered or pleated so as to resemble a rose and worn as a badge of office, as evidence of having won a… …
59rotifer — noun Etymology: ultimately from Latin rota + fer Date: 1793 any of a class (Rotifera of the phylum Aschelminthes) of minute usually microscopic but many celled chiefly freshwater aquatic invertebrates having the anterior end modified into a… …
60spherical angle — noun Date: 1678 the angle between two intersecting arcs of great circles of a sphere measured by the plane angle formed by the tangents to the arcs at the point of intersection …
