UNLESS

[conjunction] - except ifYou can't get a job unless you've got experience (= you can only get a job if you've got experience).Unless you call me to say you're not coming I'll see you at the theatre (= I will see you there if you do not call to say you're not coming).Don't promise anything unless you're 100 per cent sure (= only promise things that you're 100 per cent certain of).