tortoisen.

Etymology: Found in 15th cent. in forms tortuca, tortuce, tortuge, tortu, tortuse, tortose. Tortūca (c1255 in Albertus Magnus Animal. 24 §126, 25 §59) was the late popular Latin name (see below), which later regularly became, as still in Provençal and Spanish, tortuga, and in French tortue. (Diefenbach cites also medieval Latin turtus, tortus.) Of the English forms, tortuce evidently represented the Latin, tortue and tortu the French, and the 16th cent. tortuga the Spanish form. Tortuse was probably a mere variant of tortuce (compare lettuce, letuse below); tortose and the later forms in -esse, -ise, -oise, being further variants, partly at least due to shifting of stress and obscuration of the vowel. The forms in final -s may have arisen simply from dropping -e mute; but some of them may have come from taking the possessive tortu's, tortou's, in tortou's skin, tortue's shell, as the nominative. The form tortoise appears c1569, preceded by tortoyse, 1552. The late popular Latin or Romanic tortūca is commonly held to be a derivative of Latin tortus twisted, with the formative suffix seen in Latin carrūca, festūca, lactūca, verrūca, and to refer to the crooked feet of the south European species (Diez). With Latin tortūca, French tortue, English tortuce, tortuse, compare Latin lactūca, French laitue, English lettuce, letuse, and the variant forms of the last. The classical Latin name was testūdo, < testa shell, whence Italian testudine, testuggine.