Antonyms for the word "in-definite" are "exact," "precise," "definite," "specific," "defined," and "determinate." These words describe something that is clear, definite, and unambiguous. When something is exact, there is no confusion or ambiguity involved. Precise means that the measurement or description is accurate, and no guesswork is involved. Definite suggests something that is specific and clearly defined, whereas specific means that something is precise, detailed, and specific in terms of requirements or characteristics. Defined means that something has clear boundaries and is specific in structure. Finally, determinate refers to something that is concluded or determined with certainty.