[tran.si.tion] n [L transition-, transitio, fr. transire] (1551) 1 a: passage from one state, stage, subject, or place to another: change b: a movement, development, or evolution from one form, stage, or style to another
2. a: a musical modulation b: a musical passage leading from one section of a piece to another
3: an abrupt change in energy state or level (as of an atomic nucleus or a molecule) usu. accompanied by loss or gain of a single quantum of energy -- tran.si.tion.al adj -- tran.si.tion.al.ly adv