Of forbidding or fear-inspiring aspect; fierce; stern; surly; cruel; frightful; horrible. Whose grim aspect sets every joint a-shaking. (Shak). The ridges of grim war. (Milton)
Synonym: Fierce, ferocious, furious, horrid, horrible, frightful, ghastly, grisly, hideous, stern, sullen, sour.
Origin: as. Grim; akin to g. Grimm, equiv. To g. & D. Grimmig, dan. Grim, grum, Sw. Grym, Icel. Grimmr, g. Gram grief, as adj, hostile; cf. Gr, a crushing sound, to neigh.