theca

[thee-kuh]

noun, plural the·cae [thee-see] /ˈθi si/.

a case or receptacle.

Botany, Mycology.

a sac, cell, or capsule.
a sporangium.

Anatomy, Zoology. a case or sheath enclosing an organ, structure, etc., as the horny covering of an insect pupa or the loose membrane covering the spinal cord.

Nearby words

Origin of theca

1655–65; < Latin thēca, from Greek thḗkē “case, cover,” akin to tithénai “to place, put”

Related formsthe·cal, adjective

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for theca

A chronic inflammatory involvement of a theca through which an important tendon plays may cause adhesions to form.
Lameness of the Horse|John Victor Lacroix
The theca became sessile, and in its later developments much flattened (fig. 11).
Encyclopaedia Britannica, 11th Edition, Volume 8, Slice 10|Various
The pear-shaped body is encased in a theca formed by a number of polygonal plates, and is attached by its narrow end.
Encyclopaedia Britannica, 11th Edition, Volume 8, Slice 10|Various
This theca grows in the direction of the apex of the sicula, to which it adheres by its dorsal wall.
Encyclopaedia Britannica, 11th Edition, Volume 12, Slice 3|Various

Horizontal plates or floors found in some Corals, extending across the cavity of the "theca" from side to side.
The Ancient Life History of the Earth|Henry Alleyne Nicholson

British Dictionary definitions for theca

theca

noun plural -cae (-siː)

botany an enclosing organ, cell, or spore case, esp the capsule of a moss

zoology a hard outer covering, such as the cup-shaped container of a coral polyp

Derived Formsthecal or thecate, adjective

Word Origin for theca

C17: from Latin thēca, from Greek thēkē case; related to Greek tithenai to place

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Medicine definitions for theca