What does subliminal mean?

For all of you who asked for a formal definition of Subliminal.

sub·lim·i·nal–

adjective Psychology .existing or operating below the threshold of consciousness; being or employing stimuli insufficiently intense to produce a discrete sensation but often being or designed to be intense enough to influence the mental processes or the behavior of the individual: a subliminal stimulus; subliminal advertising.

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Based on the Random House Dictionary, © Random House, Inc. 2010.