‖ rhombus
(ˈrɒmbəs)
Also 6–8 rombus. Pl. rhombuses (7–8 -us's); 8 rhombi.
[L., a. Gr. ῥόµβος.]
1. Geom. = rhomb 1.
| 1567 J. Maplet Gr. Forest 18 Rhombus, a figure with y⊇ Mathematicians foure square: hauing the sides equall, the corners crooked. 1571 Digges Pantom. ii. vi, Admitte ABCD the Rhombus, whose Area I desire. 1672 Boyle Virtues of Gems 73 Some [of the planes] were most of kinn to a Rhombus, others to a Rhomboeides. 1672 [see rhomboid B. 1]. 1797 Encycl. Brit. (ed. 3) V. 584/2 A quadrangular prism composed of four rhombi. 1825 J. Nicholson Operat. Mechanic 688 To find the area of a parallelogram: whether it be a square, a rectangle, a rhombus, or a rhomboid. 1862 Rawlinson Anc. Mon. iv. I. 313 Mark the angles of a Rhombus very much slanted from the perpendicular. 1878 Gurney Crystallogr. 66 A six-sided prism with three rhombuses at each end. |
b. Comb., as rhombus-shaped adj.; rhombus-solid = rhomb-solid.
| 1776 J. Lee Introd. Bot. Explan. Terms 383 Rhombeum, rombus-shaped, an irregular four-sided Figure. 1795 Hutton Math. Dict. II. 373/1 Rhombus-Solid. |
2. A rhomb-shaped instrument, pattern, etc.
| 1614 Sturtevant Metallica xiv. 103 The plegnick Rhombus is an Engin of extraordinary..power. 1658 Sir T. Browne Gard. Cyrus ii, The Sheare and wedge Battles, each made of half a Rhombus. 1697 W. Dampier Voy. (1699) 499, 6 Leagues to the West of Diamond Point, which makes with three Angles of a Rhombus, and is low Land. 1772–84 Cook's Voy. (1790) V. 1731 White mats..with many red stripes, rhombuses, and other figures interwoven on one side. 1846 Holtzapffel Turning 764 Mosaic works, consisting of groups either of triangles, rhombuses, or of squares. |
3. A genus of flat-fishes comprising the turbot and the brill; a fish of this genus.
| [1686 Willughby Hist. Pisc. 93.] 1753 Chambers Cycl. Suppl., Rhombo, the name of a peculiar fish of the rhombus, or turbot kind. 1876 Van Beneden's Anim. Parasites 31 De Kay found one [sc. a cymothoe] in a Rhombus in the United States. |
4. Conch. A shell of the genus Oliva.
| 1776 Da Costa Elem. Conchol. 227 From which [rhombic shape]..I have allotted them [sc. olives] the name of Rhombi. 1797 Encycl. Brit. (ed. 3) XVII. 353/1 Panama is famous for the cylinders or rhombi. |