出典:Wiktionary
From Middle English gostly, gastlich, from 古期英語 gāstlīċ (“spiritual, holy, clerical (not lay), ghastly, ghostly, spectral”), from Proto-West Germanic *gaistalīk (“spiritual”), equivalent to ghost + -ly. Cognate with Scots ghaistly, gaistly (“spiritual, ghastly, terrifying”), West Frisian geastlik (“spiritual, clerical, religious”), Dutch geestelijk (“spiritual, clerical, ecclesiastical”), German geistlich (“spiritual, sacred, religious”), Danish geistlig (“ecclesiastical, clerical”).
ghostly (comparative ghostlier, superlative ghostliest)