Take it or leave it is an idiomatic expression that refers to presenting an offer or proposition that is somewhat inflexible, and that the other party can either accept or reject with no room for negotiation. Some synonyms for take it or leave it include "this is my final offer," "that's all there is to it," "accept or decline," "acceptance optional," and "final say." These phrases imply a sense of finality and suggest that there is little chance for bargaining or compromise. Overall, take it or leave it and its synonyms are useful in conveying decisiveness and a clear stance on an issue.