This lexeme is a hapax, and its sense must be derived from the Biblical reference to Genesis 3:15 (‘ipsa conteret caput tuum, et tu insidiaberis calcaneo eius’). The etymology is unclear. A possible emendation of the word to [n]as (i.e. ‘nose’, cf. TL nase 6,505) is suggested by Hasenohr and Bordier in their more recent edition (and translation) of the text, Genève 2017, pp. 204-08. Ruth Nisse has argued that the word may translate (and mis-transliterate) Hebrew rosh or its Arabic cognate ra, both meaning 'head'. Ruth Nisse, 'Serpent's Head / Jews Hand: Le Jeu d'Adam and Christian-Jewish Debate in Norman England', in Jocelyn Wogan-Browne, Carolyn Collette, Maryanne Kowaleski, Linne Mooney, Ad Putter and David Trotter (eds.) Language and Culture in Medieval Britain: the French of England c.1100-c.1500. York: York Medieval Press and Boydell and Brewer, 2009, 207-19 (pp. 208-9). Nisse's suggestion of a second Anglo-Norman attestation of the word in Wace's But ('Tost as un volain halt levé E tost le ras desuz buté', l. 1928) seems unlikely, and is better interpreted as a ind.pr.2 of raveir.