shake somebody/something ↔ up phrasal verb ( see also ↑ shake )
1 . to give someone a very unpleasant shock, so that they feel very upset and frightened:
She was badly shaken up by the accident.
⇨ ↑ shaken
2 . to make changes to an organization in order to make it more effective SYN overhaul :
the government’s plans to shake up the educational system
⇨ ↑ shakeup