Principal English Translation:
to frown in anger (see Karttunen); to become angry
Frances Karttunen:
ZŌMĀ vrefl, pret: ZŌMAH to frown in anger / yo tengo ceño como enojado (C for first pers. sg. subject).
Frances Karttunen, An Analytical Dictionary of Nahuatl (Norman: University of Oklahoma Press, 1992), 348.
Attestations from sources in English:
mozōma = he's angry
Michel Launey, An Introduction to Classical Nahuatl, translated and adapted by Christopher MacKay (Cambridge: Cambridge University Press, 2011), 195.
zōma = irritate, annoy
Michel Launey, An Introduction to Classical Nahuatl, translated and adapted by Christopher MacKay (Cambridge: Cambridge University Press, 2011), 57.
Attestations from sources in Spanish:
çoma, zoma = enojarse
Rémi Siméon, Diccionario de la lengua náhuatl o mexicana (Mexico: Siglo XXI, 1996), xxxvi.