Perfect Rhymes:
* abrogation
* allegation
* agitation
* appreciation
* calculation
* congregation
* degeneration
* delegation
* disintegration
* education
* elucidation
* emulation
* evacuation
* exaggeration
* exhortation
* formation
* frustration
* graduation
* imagination
* intimation
* investigation
* mitigation
* navigation
* obligation
* pagination
* participation
* penetration
* perpetuation
* preservation
* proliferation
* recreation
* regulation
* reiteration
* relocation
* reputation
* resignation
* segregation
* stimulation
* subjugation
* suggestion
* vibration
Near Rhymes:
* coagulation
* propagation
* refrigeration
* accommodation
* decontamination
These words vary in their level of formality and common usage.
Remember that the best rhyming word for "conjugation" depends on the context of your writing.