The Collaborative International Dictionary of English v.0.48:

biofeedback \bi`o*feed"back\ n.
   a training program in which a person is given information
   about physiological processes (heart rate or blood pressure)
   that is not normally available with the goal of gaining
   conscious control of them.
   [WordNet 1.5]

WordNet (r) 3.0 (2006):

biofeedback
    n 1: a training program in which a person is given information
         about physiological processes (heart rate or blood
         pressure) that is not normally available with the goal of
         gaining conscious control of them

Moby Thesaurus II by Grady Ward, 1.0:

64 Moby Thesaurus words for "biofeedback":
   Arica movement, Erhard Seminars Training, New Consciousness,
   Pentothal interview, SAT, T-group, assertiveness training,
   behavior modification, behavior therapy, bioenergetics,
   confrontation therapy, conjoint therapy, consciousness raising,
   counseling, directive therapy, encounter therapy, est,
   family training, feminist therapy, gestalt therapy,
   group psychotherapy, group relations training,
   group sensitivity training, group therapy, humanistic therapy,
   hypnoanalysis, hypnosis, hypnotherapy, hypnotism, marathon,
   marriage encounter, mind cure, narcoanalysis, narcohypnosis,
   narcosynthesis, narcotherapy, nondirective therapy,
   occupational therapy, pastoral counseling, play therapy,
   primal therapy, prolonged narcosis, psychodrama,
   psychological counseling, psychosurgery, psychosynthesis,
   psychotherapeutics, psychotherapy, radical therapy,
   rational-emotive therapy, reality therapy, recreational therapy,
   regression therapy, release therapy, scream therapy,
   sensitivity training, sensory awareness training, sleep treatment,
   supportive therapy, training group, transactional analysis,
   transcendental meditation, transpersonal therapy,
   vocational therapy