目瞪口呆

dumbstruck (idiom); stupefied / stunned

eye / (literary) to look; to regard / eye (of a net); mesh / mesh size; grit size (abbr. for 目數|目数[mu4 shu4]) / item; section / list; catalogue / (taxonomy) order / name; title

to open (one's eyes) wide / to stare at / to glare at

mouth / classifier for things with mouths (people, domestic animals, cannons, wells etc) / classifier for bites or mouthfuls

foolish / stupid / expressionless / blank / to stay