markup \markup\ n. 1. (Commerce) The amount added to the cost to determine the asking price. [WordNet 1.5] 2. (printing) Instructions for the typesetter that are written on the copy (e.g. underlining words that are to be set in italics). [WordNet 1.5] 3. (Legislation) Changes in proposed legislation drafted in conference, as contrasted with changes resulting from the amendment process. [PJC]