every nineteen parts; or in each nineteen (see Molina)
Orthographic Variants:
caxtulcan onnauhcan
Alonso de Molina:
caxtulcan onnauhcan. en dezi nueue partes. &c. Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 13r. col. 2. Thanks to Joe Campbell for providing the transcription.