Lacan wrote about two levels of speaking, one in which we know what we are saying (even when struggling with something difficult or contradictory) and another in which we have no idea of what we are saying. In this second level of speaking there are repeating words, phrases, and even sounds that function as magnets of unconscious meaning, condensing multiple scenes, times, and ideas. He called such markers in speech 'signifiers.
Annie Rogers, The Unsayable: The Hidden Language of Trauma
psychoanalysis, psychology, trauma