Here's what rhymes with protosign.
fine sign shine thine sine vine sein zine line design divine nine define mine wine assign pine shrine spine dine swine tine whine affine opine stein cosign benign resign align brine refine supine redefine redesign twine proline thymine aline decline confine iodine cysteine thiamine consign hyperfine malign saccharine anodyne enshrine waterline asinine reassign superfine dopamine endocrine undermine borderline incline atropine palatine pyridine underline monoamine recline byzantine crinoline entwine realign timberline interline reconsign alkaline crystalline epinephrine turpentine serpentine centerline exocrine neuroendocrine porcupine anticline recombine calamine intertwine valentine celandine disincline imipramine lacustrine columbine eglantine clementine norepinephrine concubine tetracycline polycrystalline noncrystalline Words that almost rhyme with protosign
hym heing thyme time lime rhyme dime rime slime beim chime mime chyme crime prime climb overtime clime grime lysozyme sauteing sublime birdlime anteing begrime mistime paradigm anytime pantomime onetime summertime dinnertime suppertime maritime mesenchyme wintertime flexitime environ