<p><strong>Adjective:</strong></p><ul><li>ghastlier, ghastliest.</li><li>shockingly frightful or dreadful; horrible: a ghastly murder.</li><li>resembling a ghost, especially in being very pale: a ghastly look to his face.</li><li>Synonyms: cadaverous, pallid, deathlike.</li><li>terrible; very bad: a ghastly error.</li></ul><p><strong>Adverb:</strong></p><ul><li>Also ghastlily.</li><li>in a ghastly manner; horribly; terribly.</li><li>with a deathlike quality.</li></ul>