to join someone's faction; to dare to do something or to be bold; or, to have the nerve to ask for something (see Molina)
Orthographic Variants:
teuicpa neua
Alonso de Molina:
teuicpa neua. (pret. teuicpa oneuac.) hazerse del vando de otro, atreuerse y desuergonzarse. Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 112r. col. 1. Thanks to Joe Campbell for providing the transcription.