Definition of writing 1 : the act or process of one who writes: such as a : the act or art of forming visible letters or characters specifically : HANDWRITING sense 1 b : the act or practice of literary or musical composition 2 : something written: such as a : letters or characters that serve as visible signs of ideas, words, or symbols b : a letter, note, or notice used to communicate or record c : a written composition d : INSCRIPTION 3 : a style or form of composition 4 : the occupation of a writer especially : the profession of authorshi