tlaczani.

Headword: 
tlaczani.
Principal English Translation: 

someone or something (such as a horse) that runs a lot and is light on its feet (see Molina)

IPAspelling: 
tɬɑksɑni
Alonso de Molina: 

tlaczani. el que aguija y corre mucho, o es ligero de pies.
Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 116r. col. 2. Thanks to Joe Campbell for providing the transcription.

Attestations from sources in English: 

See also the Gran Diccionario Náhuatl, citing Arenas (1611), 2:28, "huel tlacçani = corre bien (Palabras con que se suelen declarar los deffectos, ó bondades de un cavallo;" https://gdn.iib.unam.mx/diccionario/tlaczani/11639.