Definition of saltillo:
(n) :
In mostly Hispanophone countries, especially Mexico, an apostrophe-like letter (lowercase ꞌ and in some orthographies capital Ꞌ) used to represent a glottal stop.
(n) :
In Mexican languages, especially Nahuatl, a glottal stop or fricative sound.
(n) :
The capital and largest city of the state of Coahuila in Mexico.