ghastly

Old English gāstlic meant spiritual or ghostly, built from gāst (spirit or breath) and the suffix -lic (like). The word carried no particular horror in its early use. Gāstlic appears in Old English religious texts meaning of the spirit or pertaining to the soul. Its tone was solemn rather than terrifying.

By Middle English, gastly had acquired the sense of causing dread or fear — a shift from the spiritual to the frightening that mirrors how ghost itself was drifting from meaning any spirit toward meaning specifically the dead returned. The 15th-century poet John Lydgate used gastly to describe pale, horrified faces. The word was gaining its modern association with death and disfigurement, and it was still spelled without any H.

The H arrived in the 16th century by analogy with ghost, which had itself gained an H through the influence of Flemish typesetters. William Caxton established England's first printing press at Westminster in 1476 and employed compositors from the Low Countries who inserted an H into ghost following Flemish spelling conventions. Once ghost had its H, ghastly followed by the same logic, and the spelling ghastly is attested by the 1520s.

The word's meaning narrowed steadily over the following centuries. By the 18th century, ghastly typically described faces pale with terror, and by the 19th century it had extended to anything grimly unpleasant or shockingly bad. Charles Dickens used it for both the literally pale and the figuratively awful. Today the word swings between genuine horror and theatrical exaggeration, at home in both a crime report and a bad restaurant review.