Answer: AGHAST

AnswerCrossword Clue
AGHASTLeft open-mouthed, say
AGHASTHorror-struck.
AGHASTStruck with amazement.
AGHASTThunderstruck.
AGHASTTerrified.
AGHASTShowing sudden dismay.
AGHASTSimply appalled.
AGHASTShocked.
AGHASTDismayed
AGHASTAmazed
AGHASTAwfully awed
AGHASTConsternated
AGHASTShocked and awed
AGHASTTotally shaken
AGHASTRendered speechless
AGHASTHorrified.
AGHASTShocked ... SHOCKED!
AGHASTMore than surprised
AGHASTFright-filled
AGHASTTerrified
AGHASTStruck with amazement
AGHASTFilled with sudden fright
AGHASTStruck by overwhelming shock
AGHASTShocked and amazed
AGHASTStruck with consternation
AGHASTStruck with fear
AGHASTFloored
aghasthorrified
aghaststupefied with horror, also AGAST
AGHASTSpeechless
AGHASTShocked
AGHASTHorrified
AGHASTSpeechless, perhaps
AGHASTAwestruck
AGHASTDeeply dismayed
AGHASTAppalled
AGHASTHorror-struck
AGHASTFear-stricken
AGHASTThunderstruck
AGHASTWhite as a sheet