a small mass of matter of irregular shape; an irregular or shapeless mass; as, a lump of coal; a lump of iron ore.-a mass or aggregation of things.-a projection beneath the breech end of a gun barrel.-to throw into a mass; to unite in a body or sum without distinction of particulars.-to take in the gross; to speak of collectively.-to get along with as one can, although displeased; as, if he does n't like it, he can lump it.