1540s, "matter which settles at the bottom of water or other liquid," from French sédiment (16c.) and directly from Latin sedimentum "a settling, sinking down," from stem of sedere "to settle, sit" (from PIE root *sed- (1) "to sit").
adjective and noun word-forming element, in most cases from Latin -arius, -aria, -arium "connected with, pertaining to; the man engaged in," from PIE relational adjective suffix *-yo- "of or belonging to." The neuter of the adjectives in Latin also were often used as nouns (solarium "sundial," vivarium, honorarium, etc.). It appears in words borrowed from Latin in Middle English. In later borrowings from Latin to French, it became -aire and passed into Middle English as -arie, subsequently -ary.
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Definitions of sedimentary
resembling or containing or formed by the accumulation of sediment;