cestus (n.1)

"a girdle," a belt worn around the waist in ancient Greece, 1570s, from Latinized form of Greek kestos, noun use of an adjective meaning "stitched, embroidered," from kentein "to prick," from PIE root *kent- "to prick, jab" (see center (n.)). Especially the magical love-inspiring girdle of Aphrodite/Venus.

cestus (n.2)

kind of weighted leather boxing glove among the Greeks and Romans, 1734, from Latin caestus, which is probably from caedere "to strike" (from PIE root *kae-id- "to strike"), but perhaps the Latin noun is from Greek kestos (see cestus (n.1)) and the thing so called because it was bound around the hand and wrist.