Meaning

noun a thin mortar that can be poured and used to fill cracks in masonry or brickwork

verb bind with grout

originFrom Middle English growte, grut, from Old English grūt (“dregs; coarse meal”), from Proto-West Germanic *grūt, from Proto-Germanic *grūtą (compare Dutch gruit (“dregs”), German Grauß, Norwegian grut (“ground”)), lengthening of Proto-Germanic *grutą, ultimately from Proto-Indo-European *gʰer- (“to grind, rub”). Related to grit.

Etymology from Wiktionary, CC BY-SA 3.0