interchange
     n 1: a junction of highways on different levels that permits
          traffic to move from one to another without crossing
          traffic streams
     2: mutual interaction; the activity of interchanging or
        reciprocating [syn: {reciprocation}, {give-and-take}]
     3: reciprocal transfer of equivalent sums of money especially
        the currencies of different countries; "he earns his
        living from the interchange of currency" [syn: {exchange}]
     v 1: give to, and receive from, one another; "Would you change
          places with me?"; "We have been exchanging letters for a
          year" [syn: {exchange}, {change}]
     2: cause to change places; "interchange this screw for one of a
        smaller size" [syn: {counterchange}, {transpose}]
     3: reverse (a direction, attitude, or course of action) [syn: {tack},
         {switch}, {alternate}, {flip}, {flip-flop}]
Source: WordNet® 2.0