[ thee-kuh ]
/ ˈθi kə /
Save This Word!

noun, plural the·cae [thee-see]. /ˈθi si/.
a case or receptacle.
Botany, Mycology.
  1. a sac, cell, or capsule.
  2. 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.
Were you ready for a quiz on this topic? Well, here it is! See how well you can differentiate between the uses of "was" vs. "were" in this quiz.
Question 1 of 7
“Was” is used for the indicative past tense of “to be,” and “were” is only used for the subjunctive past tense.

Origin of theca

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


thecal, adjective
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2022

How to use theca in a sentence

British Dictionary definitions for theca

/ (ˈθiːkə) /

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 forms of theca

thecal 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

Medical definitions for theca

[ thēkə ]

n. pl. the•cae (-sē′, -kē′)
A case, covering, or sheath, such as the outer covering of the cocoon of certain insects.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

Scientific definitions for theca

[ thēkə ]

Plural thecae (thēsē′, -kē′)
A case, covering, or sheath, such as the pollen sac of an anther, the spore case of a moss, or the outer covering of the pupa of certain insects.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.