a narrow sea passage between two pieces of land; a strait (see Molina)
Alonso de Molina:
monamicyan in ilhuicac atl. estrecho de mar entre dos tierras. Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 38r. col. 2. Thanks to Joe Campbell for providing the transcription.