adjective ghastlier -·lier, ghastliest -·li·est

1. horrible; frightful
2. ghostlike; pale; haggard
3. Informal very bad or unpleasant

Etymology: ME gastli < gast, frightened, pp. of gasten, to frighten < OE gæstan < gæst, var. of gast (see ghost): meaning infl. in ME by gostlich, ghostly