Pronunciation: (im-pos'u-bul),[key] —adj. 1. not possible; unable to be, exist, happen, etc.
2. unable to be done, performed, effected, etc.: an impossible assignment. 3. incapable of being true, as a rumor.
4. not to be done, endured, etc., with any degree of reason or propriety: an impossible situation. 5. utterly impracticable: an impossible plan. 6. hopelessly unsuitable, difficult, or objectionable.