petzcaui. (pret. opetzcauh.) deslizarse, o deleznarse alguna cosa entre las manos, assi como el anguilla, o xabon mojado. Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 81r. col. 2. Thanks to Joe Campbell for providing the transcription.
Frances Karttunen:
PETZCAHUI to slip, slide / se resbala (T) [(1)Tp.173]. T gives the preterit of this as PETZCAHUIC even though it pairs with transitive PETZCOĀ as -HU(I) verbs in general pair with -OĀ verbs. See PETZCOĀ. Frances Karttunen, An Analytical Dictionary of Nahuatl (Norman: University of Oklahoma Press, 1992), 192.