The term 'Not of this World' can be summarized by four crossword solutions: ETHEREAL (8 letters), UNEARTHLY (9 letters), SUPERNATURAL (12 letters) and ALIEN (5 letters). ETHEREAL refers to something that is light, airy and delicate, while UNEARTHLY suggests something that is not from this world or beyond human experience. SUPERNATURAL implies something that is beyond the laws of nature, and ALIEN suggests something that is foreign or unfamiliar. All four words describe something that is not of this world.