Principal English Translation:
an estuary; a water nook (see attestations)
Alonso de Molina:
axumulli. estero de mar.
Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 10r. col. 2. Thanks to Joe Campbell for providing the transcription.
Attestations from sources in English:
axomulli = a water nook
Angel Julián García Zambrano, "Ancestral Rituals of Landscape Exploration and Appropriation among Indigenous Communities in Early Colonial Mexico," in Sacred Gardens and Landscapes: Ritual and Agency, ed. Michel Conan (Washington, D.C.: Dumbarton Oaks Research Library and Collection, Harvard University Press, 2007), 194.
Attestations from sources in Spanish:
"Hay golfos (aitectli, aitic o ayolloco), estuarios (axomolli), estrechos (imonamicyan in ilhuicaatl, ipitzahuayan in ilhuicaatl, itzoliuhyan in ilhuicaatl)."
Alain Musset, El agua en el valle de México, siglos XVI-XVIII (1992), 42.
"Axomolli o axomulli (de atl, agua y xomolli o xomulli, “rincón” o “en el rincón” (Siméon, (1977) 1996: 50, 778) es el nombre en lengua nahuatl con que uno de estos parajes, seleccionado como lugar de asentamiento, aparece...."
Estudios históricos: arquitectura y diseño 4-6 (1999), 23.