A sudden feeling of worry, shock, or dismay — the jolt when something unexpected and unwelcome happens. It is a fairly formal, written word, more at home in news and stories than in the playground. A very common shape is “to someone’s consternation”: the thing happens, and people are thrown. It is stronger than ordinary worry, and a bit more public than private fear: people look taken aback. In everyday talk you would probably just say “everyone was shocked” or “we were really worried.”