tiacauh.

Headword: 
tiacauh.
Principal English Translation: 

one valiant in war, warrior

James Lockhart, Nahuatl as Written: Lessons in Older Written Nahuatl, with Copious Examples and Texts (Stanford: Stanford University Press and UCLA Latin American Studies, 2001), 235.

IPAspelling: 
tiɑhkɑːw
Alonso de Molina: 

tiacauh. valiente hombre, animoso y esforzado soldado.
Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 112v. col. 2. Thanks to Joe Campbell for providing the transcription.

Frances Karttunen: 

TIAHCĀUH someone brave, valiant / valiente hombre, animoso y esforzado soldado (M) [(1)Bf.8r,(3)Cf.109v,120r]. This contrasts with TIĀCHCĀUH 'older brother,' although they are probably cognates.
Frances Karttunen, An Analytical Dictionary of Nahuatl (Norman: University of Oklahoma Press, 1992), 240.

Lockhart’s Nahuatl as Written: 

pl. tiahcāhuān. originally tēāhcāuh, possibly related to tēāchcāuh. 235

Attestations from sources in English: 

in tiacauh, aixco eoaliztli, atlauitequiztli, apeoaltiliztli, tlapaltic, chicactic chicaoac = [In] the valiant man [are] invincibility, robustness, unconquerability. (central Mexico, sixteenth century)
Fr. Bernardino de Sahagún, Florentine Codex: General History of the Things of New Spain; Book 10 -- The People, No. 14, Part 11, 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), 23.

ca huehueyntin yaotiacahuan catca quetzalpatzactli = great, brave warriors. The quetzal feather crest device was their insignia; they bore it upon their backs in battle. (central Mexico, early seventeenth century)
Codex Chimalpahin: Society and Politics in Mexico Tenochtitlan, Tlatelolco, Culhuacan, and Other Nahuatl Altepetl in Central Mexico; The Nahuatl and Spanish Annals and Accounts Collected and Recorded by don Domingo de San Antón Muñón Chimalpahin Quauhtlehuanitzin, eds. and transl. Arthur J. O. Anderson and Susan Schroeder (Norman: University of Oklahoma Press, 1997), vol. 1, 144–145.

themes: 
Behavior, Personality
War, Conflict