T0127400 (tĕs′tŏn′) also tes·toon(tĕ-sto͞on′)n.1. A 16th-century French silver coin.2. An English coin stamped with the image of Henry VIII's head. Also called tester3.[French, from Italian testone, augmentative of testa, head, from Late Latin, skull, from Latin, shell.]