huaqui.

Headword: 
huaqui.
Principal English Translation: 

something dry (noun); to become lean; to wither; to dry up, to dry out, for there to be a drought (an intransitive verb) (see Molina, Karttunen, and Lockhart)

Orthographic Variants: 
uacqui, uaqui, huāqui, oaqui
IPAspelling: 
wɑːki
Alonso de Molina: 

Vacqui. cosa seca, enxuta, o emmagrecida.
uaqui. ni. (pret. oniuac.) secarse, enxugarse al sol, mermar las cosas liquidas, o pararse flaco.
Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, f. 154r.

Vaqui. ni. secarse, enxugarse al sol, mermar las cosas liquidas, o pararse flaco. Pre. oniuac.
Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, f. 155r.

Frances Karttunen: 

HUĀQU(I) to dry out, evaporate, wither / secarse, enjugarse al sol, mermar las cosas líquidas o pararse flaco (M) HUĀCOHUA nonact. HUĀQU(I) HUĀQUĪTIĀ caus. HUĀQU(I) HUAHHUĀQU(I) redup. HUĀQU(I).
Frances Karttunen, An Analytical Dictionary of Nahuatl (Norman: University of Oklahoma Press, 1992), 81.

Lockhart’s Nahuatl as Written: 

ni. to get dry. Class 2: ōnihuāc. Often seen as tlahuāqui, for things to get dry, for there to be a drought
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), 218.

Attestations from sources in English: 

The transitive of huāqui (it dries up) is huātza, to cause to dry up. (colonial Mexico)
Michel Launey, An Introduction to Classical Nahuatl, translated and adapted by Christopher MacKay (Cambridge: Cambridge University Press, 2011), 197.

huahuac = it dried up (preterite)
huaqui = to dry out (too much)
Robert Haskett and Stephanie Wood's notes from Nahuatl sessions with James Lockhart and subsequent research.

oaqui = it becomes lean; quauhoaqui = it becomes very lean (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), 97.