placoid Syllabification: (plac·oid)Pronunciation: /ˈplakoid/Definition of placoid adjective Zoology (of fish scales) toothlike, being made of dentin with a pointed backward projection of enamel, as in sharks and rays. Compare with ctenoid and ganoid.Origin: mid 19th century: from Greek plax, plak- 'flat plate' + -oidplacoid in other Oxford dictionaries Definition of placoid in the British & World English dictionary
