As a Noun: 1. Something which is given to someone at the same time they give you something. English = exchange. 2. A business deal in which someone buys a new car, washing machine, etc. at a reduced price by giving an old car, washing machine, etc. as well as money in payment. English = trade in. 3. The change of the use of something to another use; or the change in religious beliefs from one religion to another. English = conversion. 4. [With stress] A complete change in something. English = transformation. As a Verb or Adjective: 1. Of two or more people, to give each other something at the same time; to replace one thing with another, especially something you have bought, because the other thing is more satisfactory or more useful. English = exchange. 2. To buy a new car, washing machine, etc. at a reduced price by giving an old car, washing machine, etc. as well as money in payment. English = trade in. 3. To change the use of something from one thing to another; or to change religious beliefs from one religion to another. English = convert. 4. [With stress] to completely change something. English = transform.