Intrusive may refer to: * Intrusiveness, a typically unwelcome behavior, interrupting and disturbing to others * Intrusive rock, intrusion of molten magma leaving behind igneous rock * Saltwater intrusion, the movement of saline water into freshwater aquifers * Intrusive thought, an unwelcome involuntary thought, image, or unpleasant idea * Linking and intrusive R, in phonetics

See also