to say or affirm that one is young of age, when the truth is the opposite (see Molina)
IPAspelling:
piːpilmɑti
Alonso de Molina:
pipilmati. nino. lo mismo es que pipilitoa. Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 82r. col. 2. Thanks to Joe Campbell for providing the transcription.