what, what with, why
why, what for, interrogative unless preceded by in
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), 239.
to what end? what use? (see Karttunen)
what? (interrogative), but when preceded by in, that which (see Lockhart, Karttunen, and Molina)
what? what may it be? (see Karttunen)
what in the world? what the devil? (see Karttunen)
why? (see Karttunen)
a personal name, "What in the World For?" James Lockhart (The Nahuas, 1992, 121) translated this name from the c. 1580 census of Culhuacan.
in an incense spoon Gran Diccionario Náhuatl, citing A. Wimmer (2004), who cite the Florentine Codex, Book 8, https://gdn.iib.unam.mx/diccionario/tlemaco/73592
a clay censer or something similar for carrying fire (see Molina), an incense ladle, a hand-held brazier
to make fire with a hand drill made from a stick (see Molina)