registrar vs rapporteur

registrar and rapporteur both are nouns.

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

As nouns, rapporteur is a hyponym of registrar; that is, rapporteur is a word with a more specific, narrower meaning than registrar:

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

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