Principal English Translation: 

shield-flower, a sunflower; seems to have war associations

Orthographic Variants: 
chimalaxochitl, chimalacaxochitl
Attestations from sources in English: 

This was also apparently the name of a thirteenth-century young woman who was captured and tormented in 1299, suffering so much that she begged to be sacrificed. Her name shows some considerable variation in orthography: Chimalxochitl, Chimalaxochitl, and Chimalacaxochitl, across various sources.
See, for example, Camilla Townsend, Annals of Native America: How the Nahuas of Colonial Mexico Kept their History Alive (Oxford: Oxford University Press, 2017), 28, 231.

Attestations from sources in Spanish: 

"Durante la fiesta 1 técpatl, que se dedicaba a Huitzilopochtli, ofrecían los. antiguos mexicanos unas flores llamadas chimalxóchitl (flor de escudo) al ídolo referido."
Tlatelolco: fuentes e historia, eds. Robert Hayward Barlow, ‎Jesús Monjarás Ruiz, y ‎Elena Limón (Puebla: Universidad de las Américas y el Instituto Nacional de Antropología e Historia, 1989), 196.

"La flor de la guerra (chimalxochitl) brotó cuando se dió la guerra."
Robert H. Barlow, Tlatelolco a través de los tiempos, vol. 1 (1944), 43.