mientras.

(a loanword from Spanish)

Headword: 
mientras.
Principal English Translation: 

while, during, at the same time
(a loanword from Spanish)

Attestations from sources in English: 

OnniquinCauhtiPan cali Para quinmoCuyhu[...]que Mientras Dios quimmoneMiltilis (Metepec, 1795)
Beyond the Codices, eds. Arthur J.O. Anderson, Frances Berdan, and James Lockhart (Los Angeles: UCLA Latin American Center, 1976), Doc. 6.