Relaxing rhymes with:
faxing, taxing, waxing, affixing, annexing, boxing, coaxing, faxing, fixing, flexing, indexing, intermixing, mixing, outfoxing, perplexing, taxing, vexing, waxing, xeroxing
Relaxing sounds like:
realigning, realizing, releasing, religion's, religions, relishing, rollicking