The Collaborative International Dictionary of English v.0.48:

Matriculation \Ma*tric`u*la"tion\, n.
   The act or process of matriculating; the state of being
   matriculated.
   [1913 Webster]

WordNet (r) 3.0 (2006):

matriculation
    n 1: admission to a group (especially a college or university)
         [syn: matriculation, matric]

Moby Thesaurus II by Grady Ward, 1.0:

23 Moby Thesaurus words for "matriculation":
   booking, cataloging, chronicling, enlistment, enrollment, entering,
   entry, impanelment, indexing, inscribing, inscription, insertion,
   inventorying, listing, logging, posting, record keeping,
   recordation, recording, register, registration, registry,
   tabulation