Search Result for "zona": 
Wordnet 3.0

NOUN (1)

1. (anatomy) any encircling or beltlike structure;
[syn: zone, zona]


The Collaborative International Dictionary of English v.0.48:

Zona \Zo"na\, n.; pl. Zonae. [L., a girdle. See Zone.] A zone or band; a layer. [1913 Webster] Zona pellucida. [NL.] (Biol.) (a) The outer transparent layer, or envelope, of the ovum. It is a more or less elastic membrane with radiating striae, and corresponds to the cell wall of an ordinary cell. See Ovum, and Illust. of Microscope. (b) The zona radiata. Zona radiata [NL.] (Biol.), a radiately striated membrane situated next the yolk of an ovum, or separated from it by a very delicate membrane only. [1913 Webster]
WordNet (r) 3.0 (2006):

zona n 1: (anatomy) any encircling or beltlike structure [syn: zone, zona]