bolillo

[ buh-lee-oh; Spanish baw-lee-yaw ]
/ bəˈli oʊ; Spanish bɔˈli yɔ /

noun, plural bo·lil·los [buh-lee-ohz; Spanish baw-lee-yaws] /bəˈli oʊz; Spanish bɔˈli yɔs/. Mexican Cookery.

a crusty hard roll with a soft center.
a sandwich made with this roll.

Origin of bolillo

< Spanish, equivalent to boll(o) bun, roll (with gender change < Latin bulla bubble, knob; cf. bola, boil1) + -illo diminutive suffix