ezquizaliztli.

Headword: 
ezquizaliztli.
Principal English Translation: 

menstruation; or a woman's blouse (see Molina)

Alonso de Molina: 

ezquizaliztli. costumbre tal de muger, o su camisa.
Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 29v. col. 2. Thanks to Joe Campbell for providing the transcription.

Attestations from sources in English: 

Literally, the emergence or flow of blood.