13 letters · 18 points in Scrabble
noun the muscle in the back part of the leg that forms the greater part of the calf; responsible for the plantar flexion of the foot
origin1670s, borrowed from New Latin gastrocnēmius, from Ancient Greek γαστροκνημία (gastroknēmía, “calf of the leg”), from γαστήρ (gastḗr, “paunch, belly”) + κνήμη (knḗmē, “leg”).
Etymology from Wiktionary, CC BY-SA 3.0