A girdle or belt worn in ancient Greece and Rome, sometimes used in athletics or as an ornament; also the zone or girdle of a mollusk.
From Latin cestus, from Greek zōstēr (girdle, zone), related to zōnnymi (to gird or encircle).
In zoology, the 'cestus' or girdle of snails and clams is a muscular band that helps them move—the Romans borrowed the word from Greeks to describe human belts, and biologists kept it for animal anatomy!
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