Definition of Trigonia
1 : a genus of pearly-shelled bivalve mollusks (suborder Arcacea) including many extinct forms which characterize the Mesozoic rocks and a few living forms which survive on the coast of Australia
2 [New Latin; from the often triangular shape of the fruit] : a genus (the type of the family Trigoniaceae) of chiefly climbing tropical American shrubs
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Origin and Etymology of trigonia
New Latin, from Latin trigonus triangular (from Greek trigōnos) + New Latin -ia; from the shells suggesting the form of a triangle
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