theca

[thee-kuh]

noun

plural

thecae 

1. a case or receptacle.

2. Botany, Mycology.

   1. a sac, cell, or capsule.

   2. a sporangium.

3. 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.

theca

/ ˈθiːkə /

noun

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

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

theca

plural

thecae 

1. 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.

Other Word Forms

• thecal adjective

Word History and Origins

Origin of theca¹

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

Word History and Origins

Origin of theca¹

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

Example Sentences

The graptolites built many theca together to form a branching structure that then drifted in ancient seas and therefore can be found in sedimentary rocks of a certain vintage all around the world.

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This theca grows in the direction of the apex of the sicula, to which it adheres by its dorsal wall.

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Before the latter plates arose, the stem had developed by the elongation and constriction of the fixed end of the theca, the gradual regularization of the plates involved, and their coalescence into rings.

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Corals have been divided into Aporosa and Perforata, according as the theca and septa are compact and solid, or are perforated by pores containing canals lined by endoderm.

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When the theca of the cord is directly infected the spinal symptoms predominate at first, but as the condition progresses it involves the cerebral membranes, and symptoms of acute general lepto-meningitis ensue.

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