or else

Definition

B2 used to say what will happen if another thing does not happen: We must be there by six, or else we'll miss the beginning.Either, or, neither, nor B2 used to compare two different things or situations: She's either really talkative and you can't shut her up or else she's silent.Either, or, neither, nor › informal used as a threat, sometimes humorously: He'd better find it quickly, or else (= or I will punish him in some way)!Dangers and threats

(Definition of or else from the Cambridge Advanced Learner's Dictionary & Thesaurus © Cambridge University Press)