The act of intruding, or of forcing in; especially, the forcing (one's self) into a place without right or welcome; encroachment.
- The act of intruding or the condition of being intruded on.
- An inappropriate or unwelcome addition.
- Law Illegal entry upon or appropriation of the property of another.
- Geology The forcing of molten rock into an earlier formation.
- Geology The rock mass produced by an intrusive process.