The Collaborative International Dictionary of English v.0.48:

behaviorism \behaviorism\ n.
   an approach to psychology that emphasizes observable
   measurable behavior.

   Syn: behaviourism, behavioristic psychology, behaviouristic
        psychology.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

behaviorism
    n 1: an approach to psychology that emphasizes observable
         measurable behavior [syn: behaviorism, behaviourism,
         behavioristic psychology, behaviouristic psychology]

Moby Thesaurus II by Grady Ward, 1.0:

54 Moby Thesaurus words for "behaviorism":
   Adlerian psychology, Freudian psychology, Freudianism,
   Gestalt psychology, Horneyan psychology, Jungian psychology,
   Marxism, Pavlovian psychology, Reichian psychology,
   Skinnerian psychology, Watsonian psychology, analytical psychology,
   animalism, apperceptionism, association psychology, associationism,
   atomism, behavior therapy, behavioristic psychology,
   commonsense realism, configurationism, dialectical materialism,
   dianetics, earthliness, empiricism, epiphenomenalism,
   historical materialism, hylomorphism, hylotheism, hylozoism,
   materialism, mechanism, mental chemistry, metapsychology,
   natural realism, naturalism, new realism, orgone theory,
   physicalism, physicism, positive philosophy, positivism,
   pragmaticism, pragmatism, psychoanalysis, psychoanalytic theory,
   realism, representative realism, secularism,
   stimulus-response psychology, structuralism, substantialism,
   temporality, worldliness