—adj. (ghastlier, ghastliest)
1 horrible, frightful.
2 colloq. objectionable, unpleasant.
3 deathlike, pallid.
—adv. in a ghastly or sickly way (ghastly pale).
Derivatives:
ghastlily adv. ghastliness n.
Etymology: ME gastlich f. obs. gast terrify: gh after ghost
Useful english dictionary. 2012.