The phrase "bent over backward" typically means to put in immense effort or go to great lengths to accommodate someone or achieve something. Antonyms for this phrase include being inflexible, refusing to compromise, being rigid, uncompromising, unbending, and unyielding. Alternatively, one can opt for a more casual approach and say that someone is not going out of their way or simply not making an effort. These opposing terms are useful for conveying the opposite meaning of bending over backward, which could be desirable in situations where too much effort is considered unnecessary or undesirable.