The word "un-inflected" refers to a word or phrase that has no changes in its form to indicate grammatical features such as tense, mood, or gender. The antonyms for "un-inflected" are "inflected" and "conjugated." Inflected words have different forms that indicate tense, mood, or gender, while conjugated words have different forms that indicate person, number, tense, aspect, mood, voice, and so on. For example, the word "walk" is un-inflected because it has the same form for present and past tenses. However, the word "run" is inflected because it has different forms for "run," "ran," and "running.