DDG has a bang !rhyme that redirects you over to
rhymezone. They do homo
phones, but not homonyms. Perhaps you could send some feedback upstream and see if they'll possible consider your feature request.
A query for "homonyms" shows up several lists. Maybe the community can decide which is best and DDG can scrape one of them
with permission from the authors and display them in a similar manner it does for catagory listing.
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pierce