The term 'not yet proven' can be described by four crossword solutions: UNTESTED (8 letters), posited (7 letters), THEORETICAL (11 letters), and ALLEGED (7 letters). UNTESTED means that something has not been examined or tried out. Posited implies that something has been suggested or proposed, but not necessarily proven. THEORETICAL suggests that something is based on a hypothesis or theory, rather than on facts or evidence. Finally, ALLEGED indicates that something is claimed to be true, but not yet confirmed.