The Collaborative International Dictionary of English v.0.48:

Attendance \At*tend"ance\, n. [OE. attendance, OF. atendance,
   fr. atendre, F. attendre. See Attend, v. t.]
   1. Attention; regard; careful application. [Obs.]
      [1913 Webster]

            Till I come, give attendance to reading. --1 Tim.
                                                  iv. 13.
      [1913 Webster]

   2. The act of attending; state of being in waiting; service;
      ministry; the fact of being present; presence.
      [1913 Webster]

            Constant attendance at church three times a day.
                                                  --Fielding.
      [1913 Webster]

   3. Waiting for; expectation. [Obs.]
      [1913 Webster]

            Languishing attendance and expectation of death.
                                                  --Hooker.
      [1913 Webster]

   4. The persons attending; a retinue; attendants.
      [1913 Webster]

            If your stray attendance by yet lodged. --Milton.
      [1913 Webster]

WordNet (r) 3.0 (2006):

attendance
    n 1: the act of being present (at a meeting or event etc.) [syn:
         attendance, attending] [ant: nonattendance]
    2: the frequency with which a person is present; "a student's
       attendance is an important factor in her grade"
    3: the number of people that are present; "attendance was up by
       50 per cent"

Moby Thesaurus II by Grady Ward, 1.0:

43 Moby Thesaurus words for "attendance":
   appearance, assemblage, assembly, attendant, attending, audience,
   being, body of retainers, box office, cohort, cortege, court,
   crowd, draw, employ, employment, entourage, follower, following,
   frequence, frequenting, gate, gathering, house, ministration,
   ministry, number present, parasite, peonage, presence, retinue,
   rout, satellite, serfdom, serving, servitium, servitorship,
   servitude, slavery, suite, tendance, train, turnout