Antonyms for the phrase "be predisposed" include words like disinclined, reluctant, unwilling, indifferent, and uninterested. These words imply a lack of eagerness or inclination towards a particular course of action or mindset, contrary to being predisposed, which implies a natural inclination or tendency. Being disinclined or reluctant suggests a resistance or lack of desire towards a particular thing, while being indifferent point towards a lack of preference either way. Ultimately, the choice of antonym will depend on the context and tone of the sentence in which "be predisposed" is being used.