in antiquity, a little vase or cup used at table to serve up sauce or seasoning. It also denotes notes a Roman measure, both for liquid and dry things, equal to a cyathus and a half.

in anatomy, a cavity in any bone for receiving the protuberant head of another, and thereby forming that species of articulation called **synarthrosis**. See **Anatomy**, Part I.

in botany, the trivial name of a species of the peziza, or cup-peziza, a fungus belonging to the cryptogamic fungi of Linnaeus. It has got the name of acetabulum from the resemblance its leaves bear to a cup. See **Peziza**.