B1[C or U](the emotional or physical reaction to) a sudden, unexpected, and usually unpleasant event or experience: Her mother's death came as a great shock - it was so unexpected.It was such a loud crash - it gave me/I got quite a shock.It was a shock to see her looking so ill.I was in (a state of) shock for about two weeks after the accident.UKThe French suffered a shock defeat(= completely unexpected defeat) by the Italian side at the weekend.Surprising and shockingMaking people sad, shocked and upsetMaking people sad, shocked and upseta shock to the system›an unpleasant feeling that you experience when something new or unusual happens: It's really hard getting back to work after three months off - it's quite a shock to the system.Difficult situations and unpleasant experiencesAccidents and disasters