operculum

Borrowed from Latin operculum.

• (UK) IPA^(key): /əʊˈpɜː.kjʊ.ləm/
• (US) IPA^(key): /oʊˈpɝ.kjə.ləm/

operculum (plural opercula)

1. (zoology) A covering flap in animals, such as a gill cover.
   • 2017 January 18, Susannah Lydon, The Guardian‎:

     Hyoliths […] have a small, conical calcium carbonate shell, with a lid called an operculum.

2. (botany) The lidlike portion of a moss sporangium or of a fruit that detaches to allow the dispersal of spores or seeds.
3. (dentistry) A gum flap covering (part of) a partially erupted tooth, usually a wisdom tooth.
4. A structure which serves as a cover or lid.
   • 1900 December – 1901 August, H[erbert] G[eorge] Wells, chapter IX, in The First Men in the Moon, London: George Newnes, […], published 1901, →OCLC, page 95:

     I lifted the circular operculum from its place and laid it carefully on the bale.

5. (anatomy) One of several flaps of cerebral cortex covering the insula. (clarification of this definition is needed)

• operculiferous
• operculitis
• preoperculum
• interoperculum
• suboperculum

• opercle

From operiō (“I close”) +‎ -culum.

• (Classical) IPA^(key): /oˈper.ku.lum/, [ɔˈpɛrkʊɫ̪ʊ̃ˑ]
• (modern Italianate Ecclesiastical) IPA^(key): /oˈper.ku.lum/, [oˈpɛrkulum]

operculum n (genitive operculī); second declension

1. cover, covering

Second-declension noun (neuter).

• → English: opercle, operculum
• → French: opercule
• → Italian: opercolo
• → Portuguese: opérculo
• → Spanish: opérculo

• “operculum”, in Charlton T. Lewis and Charles Short (1879) A Latin Dictionary, Oxford: Clarendon Press
• “operculum”, in Charlton T. Lewis (1891) An Elementary Latin Dictionary, New York: Harper & Brothers
• operculum in Gaffiot, Félix (1934) Dictionnaire illustré latin-français, Hachette.
• “operculum”, in Harry Thurston Peck, editor (1898), Harper's Dictionary of Classical Antiquities, New York: Harper & Brothers