nelpiloni.

Headword: 
nelpiloni.
Principal English Translation: 

belt, sash, something that wraps around the waist (see attestations)

IPAspelling: 
nelpiːloːni
Alonso de Molina: 

nelpiloni. ceñidor o faxa.
Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 66v. col. 1. Thanks to Joe Campbell for providing the transcription.

Attestations from sources in English: 

belts (for the ball game)
Fray Bernardino de Sahagún, Primeros Memoriales, ed. Thelma D. Sullivan (Norman: University of Oklahoma Press, 1997), 200.

in tlachmatl, ioan in tlalmantli: auh in vncan vel inepantla tlachtli, onoca tlecotl tlaxotlalli in tlalli, auh in jtech tlachmatl, vntetl in tlachtemalacatl manca, in aqujn ollimanj vncan tlacalaquja, vncan qujcalaquja olli: njman ic qujtlanj in jxqujch tlaçotli tlatqujtl, auh muchintin qujntlanj, in jxqujchtin tetlatlattaque, in vncan tlachco: itlaujcallo in olli, maieoatl, nelpilonj, queçeoatl = the walls and floor were smoothed. And there, in the very center of the ball court, was a line, drawn upon the ground. And on the walls were two stone, ball court rings. He who played caused [the ball] to enter there; he caused it to go in. Then he won all the costly goods, and he won everything from all who watched there in the ball court. His equipment was the rubber ball, the leather gloves, girdles, and leather hip guards.(central Mexico, sixteenth century)
Fr. Bernardino de Sahagún, Florentine Codex: General History of the Things of New Spain; Book 8 -- Kings and Lords, no. 14, Part IX, eds. and transl. Arthur J. O. Anderson and Charles E. Dibble (Santa Fe and Salt Lake City: School of American Research and the University of Utah, 1951), 29.

nima ie ic momana quimomaca in queceoatl i maiehoatl i nelpiloni = Then the leather hip-guards, the leather gloves, the belts were given out; [the players] took them up. (central Mexico, sixteenth century)
Fray Bernardino de Sahagún, Primeros Memoriales, ed. Thelma D. Sullivan, et al. (Norman: University of Oklahoma Press, 1997), 200.

in vncan oonquetzaloc in patolco, in tlachco: ca oontlatlalililoc in maiehoatl in queceoatl, in nelpilonj = when he hath been placed there in the patolli game, in the ball game; for the glove, the leather hip-guard, the girdle have been placed on (central Mexico, sixteenth century)
Fr. Bernardino de Sahagún, Florentine Codex: General History of the Things of New Spain; Book 6 -- Rhetoric and Moral Philosophy, No. 14, Part 7, eds. and transl. Arthur J. O. Anderson and Charles E. Dibble (Santa Fe and Salt Lake City: School of American Research and the University of Utah, 1961), 64.