occenca. mayormente, o principalmente. aduerbio. Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 74v. col. 2. Thanks to Joe Campbell for providing the transcription.
Frances Karttunen:
OCCENCAH principally, especially / mayormente o principalmente (M) [(3)Cf.87r,87v]. See OCCENCAH. Frances Karttunen, An Analytical Dictionary of Nahuatl (Norman: University of Oklahoma Press, 1992), 175.