Definify.com
Webster 1913 Edition
Calyptra
Ca-lyp′tra
(kȧ-lĭp′trȧ)
, Noun.
[NL., fr. Gr.
καλύπτρα
a covering for the head, fr. καλύπτειν
to cover.] (Bot.)
A little hood or veil, resembling an extinguisher in form and position, covering each of the small flasklike capsules which contain the spores of mosses; also, any similar covering body.