Principal English Translation: 

nine (see Lockhart and Karttunen)

Orthographic Variants: 
chicunahui, chiconahui, chiconaui, chicuinauhtetli, chiuhnatzin
Alonso de Molina: 

chiconaui. nueue. Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 20r. col. 2. Thanks to Joe Campbell for providing the transcription.

Frances Karttunen: 

CHIUCNĀHU(I ) nine / nueve (M) Frances Karttunen, An Analytical Dictionary of Nahuatl (Norman: University of Oklahoma Press, 1992), 53.

Lockhart’s Nahuatl as Written: 

nine; combining form chiucnāuh-. Chiucnāuhtlān. an altepetl, "place of nine." 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), 214.

Attestations from sources in English: 

chiuhnatzin oran = at 9 o'clock (San Bartolomé Capulhuac, Valley of Toluca, 1625)
Genealogical Library records, Salt Lake; Microfilm 695644, vol. I, 1612–1651, matrimonios)

chicnahui tlapoalpan cahuitl oquizquí Ynic cenmochtin yní macehualhuan = Chiucna:hui tlapo:hualpan ca:huitl o:quizqui pana ini:c cenmochtin in i:ma:cehualhua:n. = In one hundred and eighty days time all his vassals left together. (Tlaxcala, ca. 1600)
Anónimo mexicano, ed. Richley H. Crapo and Bonnie Glass-Coffin (Logan, UT: Utah State University Press, 2005), 12.

ic chicuinauhtli = ninth; see the Nahuatl-language discussion of Libra, the ninth sign of the zodiac, in Lori Boornazian Diel, The Codex Mexicanus: A Guide to Life in Late-Sixteenth-Century New Spain (Austin: University of Texas Press, 2018), 173. This spelling is suggestive of an early form (chicui-) that produced the chic-, chiuc-, numerical combining forms that were equal to "five."