aztaxelli.

Headword: 
aztaxelli.
Principal English Translation: 

double heron feather headdress
Justyna Olko, Turquoise Diadems and Staffs of Office: Elite Costume and Insignia of Power in Aztec and Early Colonial Mexico (Warsaw: Polish Society for Latin American Studies and Centre for Studies on the Classical Tradition, University of Warsaw, 2005), 139.

Orthographic Variants: 
axtaxelli, axtaxexelli
Attestations from sources in English: 

This head device was sometimes combined with the quetzal feather crest, the "quetzalmiahuayo" (spelled variously).
Justyna Olko, Turquoise Diadems and Staffs of Office: Elite Costume and Insignia of Power in Aztec and Early Colonial Mexico (Warsaw: Polish Society for Latin American Studies and Centre for Studies on the Classical Tradition, University of Warsaw, 2005), 139.

aztaxelli = "emblematic of courage in the face of death"
Gordon Whittaker, Deciphering Aztec Hieroglyphs (2021), p. 88.