Intrusive

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