rhomboidal, a.
(rɒmˈbɔɪdəl)
[ad. mod.L. rhomboīdāl-is: see rhomboid and -al1.]
1. = rhomboid A. 1.
| 1658 Sir T. Browne Gard. Cyrus ii, Perspective pictures, in their Base, horison, and lines of distances, cannot escape these Rhomboidall decussations. 1681 Grew Musæum i. v. i. 102 The figure of most of the side Scales is Rhomboidal. 1794 Kirwan Elem. Min. (ed. 2) I. 259 Oriental Garnet.., presenting either 12 rhomboidal planes, or 24 trapezoidal. 1846 M{supc}Culloch Acc. Brit. Empire (1854) I. 51 The coast of Cheshire is formed entirely of the broad rhomboidal peninsula lying between the Mersey and the Dee. 1856 Henslow Dict. Bot. Terms 159 Rhombifolius, where the leaf is rhomboidal. 1878 Bell tr. Gegenbaur's Comp. Anat. 144 In others, special differentiations of the fibres may be seen forming rhomboidal plates. |
b. Anat. (See quots.)
| 1839–47 Todd's Cycl. Anat. III. 693/1 Of the fourth ventricle.—This is a rhomboidal cavity. 1848 Quain's Anat. (ed. 5) III. 759 A longitudinal median slit, analogous to the rhomboidal sinus in birds. |
2. Cryst. = rhomboid A. 2.
| 1729 Woodward Fossils i. I. 66 A Spar..breaking into Rhomboidal Masses. 1794 Kirwan Elem. Min. (ed. 2) I. 14 Compressed rhomboidal crystals. 1836 T. Thomson Min., Geol., etc. I. 12 A right rhomboidal prism. 1854 Hooker Himal. Jrnls. I. xvii. 403 Thin seams of brown lignite, with a rhomboidal cleavage. |
3. Comb., as rhomboidal-fruited, rhomboidal-leaved, rhomboidal-ovate.
| 1758 Phil. Trans. L. 446 Dillenius's rhomboidal-fruited one [sc. plant]. 1786 Abercrombie Gard. Assist., Arr. 52 Rhomboidal leaved. 1847 W. E. Steele Field Bot. 126 Sep[als] rhomboidal-ovate, apiculate. |
Hence rhomˈboidally adv., in the form of, or so as to form, a rhomboid.
| 1833–4 J. Phillips Geol. in Encycl. Metrop. (1845) VI. 778/1 The developement of new faces or joints in it [sc. shale], which sometimes meet one another rhomboidally. 1876 Macm. Mag. XXXIV. 336 Treryn, the strange, rhomboidally-weathered, porphyritic cliff-castle. |