- 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.
Origin of theca
1655–65; < Latin thēca, from Greek thḗkē “case, cover,” akin to tithénai “to place, put”
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for thecal
At the same time the thecal plates degenerated into spicules.
These two types are, in the main, correlated with two gradual differentiations in the minute structure of the thecal plates.
The brachia rise from a corresponding number of thecal plates, “radials (RR).”
- 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
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
- Of or relating to a sheath, especially a tendon sheath.
- 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.
- 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.