a touching of the genitals (literally, Molina says, "the shameful parts")
IPAspelling:
nemɑːtokilistɬi
Alonso de Molina:
nematoquiliztli. tocamiento delas partes vergonzosas. Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 67r. col. 2. Thanks to Joe Campbell for providing the transcription.