Antonyms for the term "most realizable" can depend on the context in which the term is used. If it is used in the sense of a goal or achievement, some antonyms can include unattainable, impossible, or impractical. In the context of something tangible or concrete, antonyms can include intangible, mythical, or imaginary. In the sense of something that is true or valid, antonyms can include false, imaginary, or fabricated. Additionally, antonyms for "realizable" can include unrealizable, unachievable, or unfeasible. Therefore, identifying the right antonym for "most realizable" would require a careful consideration of the context and intended meaning.