The term 'NOT AN ORIG.' can be broken down into three crossword solutions: DUP (3 letters), IMIT (4 letters), and REPR (4 letters). DUP stands for duplicate, which means an exact copy of something. IMIT stands for imitate, which means to copy or mimic something. REPR stands for reproduce, which means to make a copy of something. All three terms refer to the act of copying something, rather than creating something original.