The term MEAN ONE can be defined by three crossword solutions: OGRE (4 letters), CUR (3 letters), and SADIST (6 letters). An OGRE is a mythical creature that is usually depicted as a large, hideous, and monstrous humanoid. A CUR is an old-fashioned term for a mean or cowardly person. A SADIST is someone who derives pleasure from inflicting pain on others. All three of these terms refer to someone who is cruel, unkind, and unpleasant.