the headstall of a halter (see Molina, i.e. jáquima)
(partially a loanword from Spanish; caballo, horse)
Orthographic Variants:
caballo temmecatl
Alonso de Molina:
cauallo temmecatl. xaquima. Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 12v. col. 2. Thanks to Joe Campbell for providing the transcription.