The Collaborative International Dictionary of English v.0.48:

Arousal \A*rous"al\, n.
   The act of arousing, or the state of being aroused.
   [1913 Webster]

         Whatever has associated itself with the arousal and
         activity of our better nature.           --Hare.
   [1913 Webster]

WordNet (r) 3.0 (2006):

arousal
    n 1: the act of arousing; "the purpose of art is the arousal of
         emotions" [syn: arousal, rousing]
    2: a state of heightened physiological activity
    3: awakening from sleep
    4: mutual sexual fondling prior to sexual intercourse [syn:
       foreplay, arousal, stimulation]

Moby Thesaurus II by Grady Ward, 1.0:

46 Moby Thesaurus words for "arousal":
   a high, aggravation, agitation, animation, arousing, awakening,
   bringing out, calling forth, drawing out, eduction,
   electrification, emotion, evocation, exacerbation, exasperation,
   excitation, excitedness, excitement, exhilaration, firing,
   fomentation, galvanization, incitation, incitement, inflammation,
   infuriation, instigation, irritation, lathering up, manic state,
   pep rally, pep talk, perturbation, provocation, rabble-rousing,
   reveille, rousing, rude awakening, steaming up, stimulation,
   stimulus, stirring, stirring up, stirring-up, whipping up,
   working up