tlalpiloni.

Headword: 
tlalpiloni.
Principal English Translation: 

a special hair binder with double feather tassels (literally, a thing used to tie something) (see Olko); also, a head band
Justyna Olko, Turquoise Diadems and Staffs of Office: Elite Costume and Insignia of Power in Aztec and Early Colonial Mexico (Warsaw: Polish Society for Latin American Studies and Centre for Studies on the Classical Tradition, University of Warsaw, 2005), 150.

Orthographic Variants: 
tlalpilonj, tlapilloni
IPAspelling: 
tɬɑlpiːloːni
Attestations from sources in English: 

tlalpiloni (noun) = an ornament for the head
Daniel Garrison Brinton, Ancient Nahuatl Poetry: Containing the Nahuatl Text of XXVII Ancient Mexican Poems (1877), 164.

From (i)lpia, "to tie." The feathers are not specified in the name of the hair ornament.
cuauhtlalpiloni = hair-binder made of eagle feathers;
quetzallalpiloni, quetzalalpiloni, quetzallalpilonj, quetzallalpilloni, quetzaltlalpiloni = quetzal feather hair-binder (the most prestigious);
xolotlalpiloni = dark yellow parrot feather hair binder (one of the attributes of Otomí warriors);
zacuantlalpiloni = hair binder with yellow and black troupial feathers from the zacuantototl
Justyna Olko, Turquoise Diadems and Staffs of Office: Elite Costume and Insignia of Power in Aztec and Early Colonial Mexico (Warsaw: Polish Society for Latin American Studies and Centre for Studies on the Classical Tradition, University of Warsaw, 2005), 151–153.

in tetepeiotl, in xivitzolli, in matemecatl, in cotzeoatl, in nacochtli, in tentetl, in tlalpilonj = the peaked cap, the turquoise diadem, the arm band, the band for the calf of the leg, the ear plug, the lip rod, the head band (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), 57.

Attestations from sources in Spanish: 

xolotlalpiloni = tocado con "plumas del pecho y la barriga [del loro]...amarillas oscuras" (Sahagún 1997, 631)
Justyna Olko, Turquoise Diadems and Staffs of Office: Elite Costume and Insignia of Power in Aztec and Early Colonial Mexico (Warsaw: Polish Society for Latin American Studies and Centre for Studies on the Classical Tradition, University of Warsaw, 2005), 150.