tlacotl.

Headword: 
tlacotl.
Principal English Translation: 

a stick, a staff, a rod, a stalk, a switch (see Karttunen and Molina); osier twigs or maguey spines (see Sahagún attestations); relates to blood-letting self-sacrifice

IPAspelling: 
tɬɑkoːtɬ
Alonso de Molina: 

tlacotl. xara, vardasca.
Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 119r. col. 2. Thanks to Joe Campbell for providing the transcription.

Frances Karttunen: 

TLACŌ-TL pl: -MEH staff, stick, switch / vara, vardasca (M) This contrasts with TLĀCOH-TLI ‘slave.’
Frances Karttunen, An Analytical Dictionary of Nahuatl (Norman: University of Oklahoma Press, 1992), 256.

Attestations from sources in English: 

tlacotl = osier twig (central Mexico, sixteenth century)
Fray Bernardino de Sahagún, Primeros Memoriales, ed. Thelma D. Sullivan, et al. (Norman: University of Oklahoma Press, 1997), 255.

tlacotl. Auh aço monacazco in titlaqujxitz, anoço monenpilco. = maguey spines. And thou shalt pass these straws either through thy ears or through thy tongue. (central Mexico, sixteenth century)
Fr. Bernardino de Sahagún, Florentine Codex: General History of the Things of New Spain; Book 1 -- The Gods; No. 14, Part 2, 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, 1950), 10.

motzintlan in ticqujxtiz, in tictlaçaz: aço çan cecen in ticqujxtiz, anoço çan ticcenqujxtiz, tictlatlaçalhuiz, yn aço centzontli, aço vntzontli, in ticqujxtiz tlacotl: = “When thou drawest it through, thou shalt cast it down behind thee, either each one {alone} as thou takest it out, or else thou shalt gather them, binding them together, even four hundred {of them}, even eight hundred of the straws, which thou shalt have passed through thy tongue. (central Mexico, sixteenth century)
Fr. Bernardino de Sahagún, Florentine Codex: General History of the Things of New Spain; Book 1 -- The Gods; No. 14, Part 2, 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, 1950), 10.