it has been some time now (since something happened) (see Molina)
Orthographic Variants:
ye cuelachic
Alonso de Molina:
yecuelachic. ratoa. s. que acaecio algo. aduerbio. Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 35r. col. 1. Thanks to Joe Campbell for providing the transcription.