Principal English Translation: 

to run fast (see Lockhart); to run lightly (see Molina); or, to cross, to move (see Lacadena)

Orthographic Variants: 
Alonso de Molina: 

payna. ni. (pret. onipain.) correr ligeramente.
Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 79r. col. 1. Thanks to Joe Campbell for providing the transcription.

Lockhart’s Nahuatl as Written: 

ni. Class 2: ōnipāīn. vowel quantity speculative. 229

Attestations from sources in English: 

pa(i)n = to cross, to move; could be used in hieroglyphic writing for the locative suffix -pan
Alfonso Lacadena, "Regional Scribal Traditions: Methodological Implications for the Decipherment of Nahuatl Writing," The PARI Journal 8:4 (Spring 2008), 13.

paina = to run fast
James Lockhart, Nahuatl as Written: Lessons in Older Written Nahuatl, with Copious Examples and Texts (Stanford: Stanford University Press and UCLA Latin American Studies, 2001), 229.