rapporteur vs registrar

rapporteur and registrar both are nouns.

Word	Noun	Adjective	Verb	Adverb
rapporteur	Yes	No	No	No
registrar	Yes	No	No	No

As nouns, registrar is a hypernym of rapporteur; that is, registrar is a word with a broader meaning than rapporteur:

rapporteur: a recorder appointed by a committee to prepare reports of the meetings
registrar: someone responsible for keeping records

Other hypernyms of rapporteur include record-keeper, recorder.

rapporteur (noun)	registrar (noun)
a recorder appointed by a committee to prepare reports of the meetings	someone responsible for keeping records
	the administrator responsible for student records
	a person employed to keep a record of the owners of stocks and bonds issued by the company