Trade-in is a term that usually refers to a commercial transaction where one item is exchanged for another. However, if you're writing or speaking about trade-in too frequently, it can become dull and repetitive. Fortunately, there are plenty of synonyms for the word that will keep your vocabulary fresh. Some possible options include exchange, swap, barter, convert, bargain, sell, replace, hand over, give in, deliver, and turn over. Each of these words conveys a slightly different nuance, so consider your audience and intent when selecting the best synonym to use. Mixing it up will give your writing or speaking an added boost of energy and interest.