a. [f. L. testāce-us consisting of tiles, shells, etc.; brick-colored; covered with a shell: see TEST sb.2 and -ACEOUS.]
† 1. Made of baked clay; pertaining to or of the nature of earthenware or a potsherd. Obs. rare.
1658. Sir T. Browne, Hydriot., iii. 22. In many Bricks, Tiles, Pots, and testaceous works.
1674. J. B[rian], Harvest Home, ii. 6. Testaceous Vessels; obnoxious To casualties, that are most various.
1675. Evelyn, Terra (1729), 15. Exotic Plants … confined … to their Wooden Cases and Testaceous prisons.
2. Having a shell, esp. a hard, calcareous, unarticulated shell. † Testaceous fish = shell-fish.
1646. Sir T. Browne, Pseud. Ep., 203. All [fishes] that are testaceous, as Oysters, Cocles, Wilks, Schollops, Muscles, are excluded.
1759. Stillingfl., trans. Biberg’s Econ. Nat., Misc. Tracts (1762), 57. Testaceous worms … eat away the hardest rocks.
1809. W. Irving, Knickerb., IV. iii. The testaceous marine animal, known commonly by the vulgar name of Oyster.
1875. C. C. Blake, Zool., 232. When the shell is so much enlarged that the contracted animal finds shelter beneath or within it, the animal is said to be testaceous.
3. Of the nature or substance of shells; shelly; consisting of a shell or shelly material.
1668. Wilkins, Real Char., 122. Exanguious Animals … whose bones are on their outside … testaceous; of a more hard and brittle substance.
1676. Grew, Exper. Luctation, i. § 21. Millipedes, Egg-shells, or any other testaceous Bodies of the same strength.
1794. Sullivan, View Nat., I. 89. The testaceous matter of marine shells.
1881. Watson in Jrnl. Linn. Soc., XV. 265. Operculum testaceous.
† b. Pharmacy. Of a medicinal powder: Prepared from the shells of animals. Obs.
1710. T. Fuller, Pharm. Extemp., 392. I think testaceous Powders exert their Virtues much easier and sooner when fine.
1789. W. Buchan, Dom. Med. (1790), 549. To give the pearl-julep, chalk, crabs eyes, and other testaceous powders.
1853. Dunglison, Med. Lex., Testaceous,… a powder, consisting of burnt shells.
4. Of the color of a tile, a flower-pot, unglazed pottery, etc.; dull red; in Zool. and Bot. applied to shades of brownish red, brownish yellow, and reddish brown.
1688. R. Holme, Armoury, II. 275/2. The upper part of the Body is testaceous, or potsheard colour.
1783. Latham, Gen. Synopsis, IV. 393. Testaceous Lark. Bill black: upper parts of the body testaceous.
1887. W. Phillips, Brit. Discomycetes, 136. Cup … testaceous yellow. Ibid., 420. Testaceous, brick-coloured,… not so bright as lateritious.
Hence Testaceousness (rare–0).
1727. Bailey, vol. II., Testaceousness, shelly Nature or Quality.
