<zoology> A pearly substance which lines the interior of many shells, and is most perfect in the mother-of-pearl.

Alternative forms: nacker and naker] See Pearl, and Mother-of-pearl.

Origin: F, cf. Sp. Nacara, nacar, It. Nacchera, naccaro, LL. Nacara, nacrum; of Oriental origin, cf. Ar. Nakir hollowed.

(01 Mar 1998)