Non-viable refers to something that cannot survive, exist or succeed. Therefore, its antonyms are words that describe the opposite. These include viable, feasible, workable, practical, achievable, doable, possible, and potential. Viable refers to something that has the capability to live, grow, function, or succeed. Feasible suggests that something is feasible, practical or workable. When something is workable, it means it can be worked on or accomplished. Practical, on the other hand, refers to something that is based on experience or observation. Achievable indicates that something is possible or attainable. Potential suggests that something is possible, capable of being or becoming something.