let out1
North American (Of lessons at school, a meeting, or an entertainment) finish, so that those attending are able to leave: his classes let out at noon...
- School begins at seven and lets out at two thirty.
- The last screening of the film festival let out at 7:30 p.m.
- What time does class let out?
See parent entry: let
let-out2 
noun British informal
An opportunity to escape from or avoid a difficult situation: the country won a let-out for its factories to continue burning dirty brown coal...
- The only let-out seems to be that emergency treatment cannot be refused.
- There are no ‘let-outs’ here, no ‘emergency rations’ or vitamin supplements off-camera.
- It might, perhaps, have been useful to say rather more about the importance of giving software purchasers a let-out should they decide not to accept the terms of the licence.