placoid
1Placoid — Plac oid, n. (Zo[ o]l.) (a) Any fish having placoid scales, as the sharks. (b) One of the Placoides. [1913 Webster] …
2Placoid — Plac oid, a. [Gr. pla x, plako s, a tablet + oid.] (Zo[ o]l.) Platelike; having irregular, platelike, bony scales, often bearing spines; pertaining to the placoids. [1913 Webster] …
3placoid — [plak′oid΄] adj. [< Gr plax, flat plate, tablet (see PLACENTA) + OID] Zool. of or having scales that are periodically shed and replaced, consisting of a dentin base and an enamel covered surface, as in cartilaginous fishes …
4placoid — adj. & n. adj. 1 (of a fish scale) consisting of a hard base embedded in the skin and a spiny backward projection (cf. CTENOID). 2 (of a fish) covered with these scales. n. a placoid fish, e.g. a shark. Etymology: Gk plax plakos flat plate …
5placoid — adjective Etymology: Greek plak , plax flat surface Date: 1842 of, relating to, or being a scale of dermal origin with an enamel tipped spine characteristic of the elasmobranchs …
6placoid — adj. [Gr. plax, plate] Plate like …
7placoid — /plak oyd/, adj. platelike, as the scales or dermal investments of sharks. [1835 45; < Gk plak (s. of pláx) something flat, tablet + OID] * * * …
8placoid — plac·oid (plakґoid) platelike or plaquelike …
9placoid — [ plakɔɪd] adjective Zoology (of fish scales) tooth like, being made of dentine with enamel, as in sharks and rays. Compare with ctenoid and ganoid. Origin C19: from Gk plax, plak flat plate + oid …
10placoid — plac·oid …
