Sinkhole rhymes with:
blowhole, buttonhole, cubbyhole, foxhole, keyhole, loophole, manhole, mousehole, pigeonhole, pinhole, posthole, pothole
Sinkhole sounds like:
samsel, sanmiguel, schenkel, schinkel, schmechel, schmeichel, seemingly, senecal, senechal, senegal, sensual, shankel, shankle, shingle, shinkle, shockingly, sinegal, singel, single, singley, singly, sinsel, smejkal, smigel, smigiel, smuggle, smugly, snackwell, snuggle, snugly, swingle, swingley, synonymously