cozamalotl.

Headword: 
cozamalotl.
Principal English Translation: 

a rainbow (see Molina and Karttunen)

Orthographic Variants: 
coçamalutl
IPAspelling: 
koːsɑmɑːloːtɬ
Alonso de Molina: 

cozamalotl. arco del cielo.
Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 23r. col. 1. Thanks to Joe Campbell for providing the transcription.

Frances Karttunen: 

CŌZAMĀLŌ-TL rainbow / arco del cielo (M), arco iris (S)
Frances Karttunen, An Analytical Dictionary of Nahuatl (Norman: University of Oklahoma Press, 1992), 43.

Attestations from sources in English: 

ayauh cozamalotl (noun) = the rainbow; lit., "mist of water jewels" Daniel Garrison Brinton, Ancient Nahuatl Poetry: Containing the Nahuatl Text of XXVII Ancient Mexican Poems (1887), 150.

themes: 
Weather, Climate