Here's what rhymes with protocanonical.
canonical monocle Words that almost rhyme with protocanonical
anatomical nautical topical follicle barnacle coracle karakul possible marginal particle cortical horrible nominal volatile carnival laudable methodical adorable farcical inaudible fontanel washable lockable watchable impossible probable soluble cardinal plausible phenomenal portable affordable allegorical constable forcible apocryphal carbonyl chargeable oratorical torsional aeronautical corpuscle voluble nonvolatile solvable unsolvable unstoppable fordable chlorophyl adoptable rhapsodical gemmological gemological remarkable abdominal hierarchical proximal doctrinal improbable insoluble orthogonal cosmological enforceable implausible etymological oligarchical supportable purchasable scatological submarginal tortoiseshell antiparticle axolotl importable suborbital insolvable equatable enlargeable responsible proportional irresponsible deplorable cytological pronominal tetragonal unenforceable unremarkable exportable resolvable entomological exhaustible gerontological rechargeable seismological nonenforceable revolvable nonchargeable epistemological inexhaustible insupportable transportable anthropological disproportional phantasmagorical