Learn how to say Aghast correctly in English with this tutorial pronunciation video.
Oxford dictionary definition of the word aghast:
filled with horror or shock:
she winced, aghast at his cruelty
late Middle English: past participle of the obsolete verb agast, gast ‘frighten’, from Old English gǣsten. The spelling with gh (originally Scots) became general by about 1700, probably influenced by ghost; compare with ghastly