<unk>  in psychoanalysis, refers to oppositional behavior when an individual's unconscious defenses of the ego are threatened by an external source. Sigmund Freud, the founder of psychoanalytic theory, developed his concept of<unk> as he worked with patients who suddenly developed uncooperative behaviors during sessions of talk therapy. He reasoned that an individual that is suffering from a psychological affliction, which Freud believed to be derived from the presence of suppressed illicit or unwanted thoughts, may inadvertently attempt to impede any attempt to confront a subconsciously perceived threat. This would be for the purpose of inhibiting the revelation of any repressed information from within the unconscious mind.
Resistance 
Drug resistance
Cross-resistance
Host adaptation
Mutation
Multiple drug resistance
Antigenic variation
Antimicrobial resistance