ipan yauh.

Headword: 
ipan yauh.
Principal English Translation: 

to hit the target with an arrow or harquebus (any small-caliber long gun) (see Molina)

Alonso de Molina: 

ipan yauh (pret. ipan oya. vel. oipanya.) dar la saeta o el arcabuz enel blanco.
Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 41v. col. 2. Thanks to Joe Campbell for providing the transcription.

Attestations from sources in English: 

Much of the meaning is implied, as no weapon is mentioned directly.

yauh + ipan + something bad = to incur (central Mexico, sixteenth century)
Personal communication, James Lockhart, in sessions analyzing Huehuetlatolli.

themes: 
Weapons, Shields, Heraldry