Definify.com

Webster 1913 Edition

Adj.

[L.

testaceus

, fr.

testa

a shell. See

Of or pertaining to shells; consisted of a hard shell, or having a hard shell.

(Bot. & Zool.)

Having a dull red brick color or a brownish yellow color.

Testaceous animals

(Zool.)

animals having a firm, calcareous shell, as oysters and clams, thus distinguished from

crustaceous animals

, whose shells are more thin and soft, and consist of several joints, or articulations, as lobsters and crabs.

testaceous ‎(comparative more testaceous, superlative most testaceous)

(obsolete) Pertaining to earthenware or baked clay.
- 1658: they were burnt, or only baked in Oven or Sunne: According to the ancient way, in many bricks, tiles, pots, and testaceous works — Sir Thomas Browne, Urne-Burial (Penguin 2005, p. 20)
Of a reddish-yellow or brownish colour, like brick.
Having a shell, especially one which is not articulated.