Note  —n. 1 brief written record as an aid to memory (often in pl.: make notes). 2 observation, usu. Unwritten, of experiences etc. (compare notes). 3 short or informal letter. 4 formal diplomatic communication. 5 short annotation or additional explanation in a book etc. 6 a = *banknote. B written promise of payment. 7 a notice, attention (worthy of note). B eminence (person of note). 8  a single musical tone of definite pitch. B written sign representing its pitch and duration. C key of a piano etc. 9 quality or tone of speaking, expressing mood or attitude etc. (note of optimism). —v. (-ting) 1 observe, notice; give attention to. 2 (often foll. By down) record as a thing to be remembered or observed. 3 (in passive; often foll. By for) be well known.  hit (or strike) the right note speak or act in exactly the right manner. [latin nota mark (n.), noto mark (v.)]