The Collaborative International Dictionary of English v.0.48:

Acceptation \Ac`cep*ta"tion\, n.
   1. Acceptance; reception; favorable reception or regard;
      state of being acceptable. [Obs.]
      [1913 Webster]

            This is saying worthy of all acceptation. --1 Tim.
                                                  i. 15.
      [1913 Webster]

            Some things . . . are notwithstanding of so great
            dignity and acceptation with God.     --Hooker.
      [1913 Webster]

   2. The meaning in which a word or expression is understood,
      or generally received; as, term is to be used according to
      its usual acceptation.
      [1913 Webster]

            My words, in common acceptation,
            Could never give this provocation.    --Gay.
      [1913 Webster]

WordNet (r) 3.0 (2006):

acceptation
    n 1: acceptance as true or valid
    2: the accepted meaning of a word [syn: word meaning, word
       sense, acceptation]
    3: the act of accepting with approval; favorable reception; "its
       adoption by society"; "the proposal found wide acceptance"
       [syn: adoption, acceptance, acceptation, espousal]

Moby Thesaurus II by Grady Ward, 1.0:

34 Moby Thesaurus words for "acceptation":
   acceptance, acception, acquiescence, assurance, assuredness,
   belief, certainty, confidence, credence, credit, credulity,
   dependence, faith, hope, import, intendment, message, purport,
   received meaning, reception, reliance, reliance on, sense,
   significance, significancy, signification, stock, store, sureness,
   surety, suspension of disbelief, trust, understanding, usage