Dic: in case

11. PHRASE : PHR with cl | You use in case in expressions like 'in case you didn't know' or 'in case you've forgotten' when you are telling someone in a rather irritated way something that you think is either obvious or none of their business.

• She's nervous about something, in case you didn't notice.

9. PHRASE | If you do something in case or just in case a particular thing happens, you do it because that thing might happen.

• In case anyone was following me, I made an elaborate detour.

..... Cobuild