n. 1 addendum, addition, appendix, epilogue, end-piece, postscript, appendage, extension, continuation, adjunct, annexe, appurtenance, accessory, codicil, insert, sequel; supplementation; Technical suppletion The later version includes the 1909 supplement
v. 2 add (on or to), extend, augment; complement Various scholars supplemented the earlier work with their own notes and comments He supplements his income by working at a restaurant.