unionoid
unionoid noun: any member of the family Unionidae or its order Unionida of freshwater mussels.
Noun
unionoid (plural unionoids)
- Any member of the family Unionidae or its order Unionida of freshwater mussels.
- II. n. Same as unionid.[1891, “unionoid (ū′ni-ọ̄-noid), a. and n.”, in William Dwight Whitney, editor, The Century Dictionary: An Encyclopedic Lexicon of the English Language […], volume VI, New York, N.Y.: The Century...
Adjective
unionoid (comparative more unionoid, superlative most unionoid)
- Relating to, resembling or characteristic of the family Unionidae or its order Unionida of freshwater mussels.
- Carbonicola, of the Devonian and Carboniferous, comprises Unionoid Bivalves, with thick shells, an external ligament, and a concentrically-striated surface.1879, Henry Alleyne Nicholson, “Unionidæ”, in A Manual of Palæontology for the Use of Students […], 2nd edition, volume I, Edinburgh; London: William Blackwood and Sons, →OCLC, page 492
- I know nothing of that of Solenaia beyond the statement of Fischer regarding its greatly developed, mushroom shaped foot and its burrowing habit. It is, I am satisfied, an unionoid animal and the fact that there is a decided posterior pallial sinus to the shell leads me to believe that it has two...1914, Charles Torrey Simpson, “Genus Solenaia Conrad, 1869”, in A Descriptive Catalogue of the Naiades, or Pearly Fresh-Water Mussels, part I (Unionidæ: Truncilla–Margaritana), Detroit, Mich.: Bryant...
- Synonyms:
- unionid, unioniform
Examples of unionoid in a sentence
- It is, I am satisfied, an unionoid animal and the fact that there is a decided posterior pallial sinus to the shell leads me to believe that it has two siphons.1914, Charles Torrey Simpson, “Genus Solenaia Conrad, 1869”, in A Descriptive Catalogue of the Naiades, or Pearly Fresh-Water Mussels, part...
- These have produced freshwater unionoid bivalves (Alathyria coatsi, Hyridella whitecliffsensis) and Australia’s oldest known non-marine gastropod – the viviparid Notopala alboscopularis.2011, Benjamin P. Kear, Robert J. Hamilton-Bruce, “Non-marine invertebrates”, in Dinosaurs in Australia: Mesozoic Life from the Southern...
Synonyms of unionoid
Forms of unionoid
| Noun | |
|---|---|
| plural | unionoids |
| Adjective | |
| comparative | more unionoid |
| superlative | most unionoid |
Origin of unionoid
From taxonomic name Unio (with insertion of -n- after its etymon, Classical Latin ūniō (stem ūniōn-)) + -oid. Compare earlier unionid and taxonomic name Unionioda.
Questions about unionoid
- What does unionoid mean?
- Unionoid means any member of the family Unionidae or its order Unionida of freshwater mussels.
- How do you use unionoid in a sentence?
- It is, I am satisfied, an unionoid animal and the fact that there is a decided posterior pallial sinus to the shell leads me to believe that it has two siphons.
- What part of speech is unionoid?
- Unionoid can be a noun or an adjective.
- What is the plural of unionoid?
- The plural of unionoid is unionoids.
Words near unionoid in the dictionary
Source and license
Adapted from Wiktionary: unionoid (page history and authors). Text available under the Creative Commons Attribution-ShareAlike 4.0 license. Word.ws reformatted the entry and added links. Wiktionary data of 2026-09-02.
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Cite this entry: “unionoid.” Word.ws, https://word.ws/unionoid. Based on Wiktionary, CC BY-SA 4.0.