ic chicumilhuitl in centetl semana.

(a loanword from Spanish)

Headword: 
ic chicumilhuitl in centetl semana.
Principal English Translation: 

Saturday (see Molina); literally, the seventh day in a week
(partly a loanword from Spanish, semana, week)

Alonso de Molina: 

icchicumilhuitl incentetl semana. el sabado.
Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 32r. col. 1. Thanks to Joe Campbell for providing the transcription.