placoid
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

New Collegiate Dictionary. 2001.

Look at other dictionaries:

  • Placoid — Plac oid, n. (Zo[ o]l.) (a) Any fish having placoid scales, as the sharks. (b) One of the Placoides. [1913 Webster] …   The Collaborative International Dictionary of English

  • Placoid — 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] …   The Collaborative International Dictionary of English

  • placoid — [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 …   English World dictionary

  • placoid — 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 …   Useful english dictionary

  • placoid — adj. [Gr. plax, plate] Plate like …   Dictionary of invertebrate zoology

  • placoid — /plak oyd/, adj. platelike, as the scales or dermal investments of sharks. [1835 45; < Gk plak (s. of pláx) something flat, tablet + OID] * * * …   Universalium

  • placoid — plac·oid (plakґoid) platelike or plaquelike …   Medical dictionary

  • placoid — [ 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 …   English new terms dictionary

  • placoid — plac·oid …   English syllables

  • placoid — plac•oid [[t]ˈplæk ɔɪd[/t]] adj. zool. platelike, as the scales or dermal investments of sharks • Etymology: 1835–45; < Gk plak (s. of pláx) something flat, tablet …   From formal English to slang

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