The Collaborative International Dictionary of English v.0.48:

Enrollment \En*roll"ment\, n. [Cf. F. enr[^o]lement.] [Written
   also enrolment.]
   1. The act of enrolling; registration. --Holland.
      [1913 Webster]

   2. A writing in which anything is enrolled; a register; a
      record. --Sir J. Davies.
      [1913 Webster]

WordNet (r) 3.0 (2006):

enrollment
    n 1: the act of enrolling [syn: registration, enrollment,
         enrolment]
    2: the body of people (such as students) who register or enroll
       at the same time [syn: registration, enrollment]

Moby Thesaurus II by Grady Ward, 1.0:

54 Moby Thesaurus words for "enrollment":
   acceptance, admission, admittance, baptism, booking, call, call-up,
   cataloging, chronicling, compulsory military service, conscription,
   draft, draft call, drafting, enlistment, entering, entry, filing,
   immission, impanelment, impressment, inauguration, indexing,
   induction, initiation, inscribing, inscription, insertion,
   installation, instatement, intromission, inventorying, investiture,
   itemization, levy, listing, logging, matriculation, mobilization,
   muster, ordination, posting, press, record keeping, recordation,
   recording, recruiting, recruitment, register, registration,
   registry, selective service, summons, tabulation



Bouvier's Law Dictionary, Revised 6th Ed (1856):

ENROLLMENT, Eng. law. The registering, or entering in the rolls of chancery,
king's bench, common pleas, or exchequer, or by the clerk of the peace in
the records of the quarter sessions, of any lawful act; as a recognizance, a
deed of bargain and sale, and the like. Jacob, L. D.