'Subliminal' definitions:

Definition of 'subliminal'

From: WordNet
adjective
Below the threshold of conscious perception

Definition of 'Subliminal'

From: GCIDE
  • Subliminal \Sub*lim"i*nal\, a. [Pref. sub- + L. limen threshold.]
  • 1. (Philos.) Existing in the mind, but below the surface or threshold of consciousness; that is, existing as feeling rather than as clear ideas. [Webster 1913 Suppl.]
  • 2. having or using an intensity of sensory stimulus insufficient to be perceived consciously, but having an effect on unconscious mental processes; as, subliminal advertising.
  • Note: The existence of such an effect is still not universally accepted. [PJC]