Ok so it seems as though everyone thinks grenadier is pronounced "gren" "aw" "dier". It's pronounced "gren" "a (and I mean a like you would say "a basket" not like you would pronounce the letter A = aw). It's just like shotgunier or bombardier. It's a person who throws grenades a grenade-ier. Correction: I was wrong lol. Saladslugger posted a link to the pronunciation below.