The Collaborative International Dictionary of English v.0.48:

Registrar \Reg"is*trar\ (-tr?r), n. [LL. registrarius, or F.
   r['e]gistraire. See Register.]
   One who registers; a recorder; a keeper of records; as, a
   registrar of births, deaths, and marriages. See Register,
   n., 3.
   [1913 Webster]

WordNet (r) 3.0 (2006):

registrar
    n 1: a person employed to keep a record of the owners of stocks
         and bonds issued by the company
    2: the administrator responsible for student records
    3: someone responsible for keeping records [syn: registrar,
       record-keeper, recorder]

Moby Thesaurus II by Grady Ward, 1.0:

41 Moby Thesaurus words for "registrar":
   CA, CPA, accountant, accountant general, actuary, amanuensis,
   archivist, auditor, bank accountant, bank examiner, bookkeeper,
   calculator, certified public accountant, chartered accountant,
   clerk, comptroller, controller, cost accountant, cost keeper,
   documentalist, engraver, filing clerk, journalizer, librarian,
   marker, notary, notary public, prothonotary, reckoner,
   record clerk, recorder, recordist, register, scorekeeper, scorer,
   scribe, scrivener, secretary, stenographer, stonecutter,
   timekeeper