Besides rhymes with:
decides, asides, coincides, decides, insides, outsides, side's, sides, sides', subsides
Besides sounds like:
backdates, backseats, backsides, backstage, backstitch, backstitches, backwoods, baghdad's, baskets, bassists, beachheads, beasts, beckwith's, beefsteak, begets, bequests, best's, bestows, bestwick, bezdek, bigots, biscuits, bisuteki, bisuteki's, boasts, bobcats, boosts, boschwitz, bostic, bostick, bostock, bostwick, bouquets, boycotts, buckets, bustos, busts