chiefly British, informal
: overwhelmed with wonder, surprise, or shock : astounded Several minutes later I touch the bottom, pleased to discover that Louise—despite all her experience exploring caves elsewhere in the world—is as gobsmacked as I am. "This place is huge, and daylit," she says, her face glazed with awe. Gregory Crouch Thus, when the cell-phone video surfaced, fashion insiders were so gobsmacked that to this day they'll tell you where they were when they first heard about it. Ingrid Sischy