intrusion

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. The act of intruding or the condition of being intruded on.
2. n. An inappropriate or unwelcome addition.
3. n. Law Illegal entry upon or appropriation of the property of another.
4. n. Geology The forcing of molten rock into an earlier formation.
5. n. Geology The rock mass produced by an intrusive process.

Century Dictionary and Cyclopedia

1. n. The act of intruding; the act of entering without warrant or justification; unbidden, unwelcome, or unfit entrance into or upon anything.
2. n. Specifically, in law: A wrongful entry after the determination of a particular estate, say for life, and before the freehold remainderman or reversioner can enter.
3. n. In English law, any trespass committed on the public lands of the crown, as by entering thereon without title, holding over after a lease is determined, taking the profits, cutting down timber, and the like.
4. n. Usurpation, as of an office.—
5. n. A thrusting or pushing in, as of something out of place; irregular or abnormal entrance or irruption: as, an intrusion of foreign matter; the intrusion of extrinsic rocks or dikes in a geological formation. See intrusive rocks, under intrusive.

Wiktionary

1. n. The forcible inclusion or entry of an external group or individual; the act of intruding.
2. n. geology Magma forced into other rock formations; the rock formed when such magma solidifies.

GNU Webster's 1913

1. n. The act of intruding, or of forcing in; especially, the forcing (one's self) into a place without right or welcome; encroachment.
2. n. (Geol.) The penetrating of one rock, while in a plastic or metal state, into the cavities of another.
3. n. (Law) The entry of a stranger, after a particular estate or freehold is determined, before the person who holds in remainder or reversion has taken possession.
4. n. (Scotch Ch.) The settlement of a minister over a congregation without their consent.

WordNet 3.0

1. n. rock produced by an intrusive process
2. n. the forcing of molten rock into fissures or between strata of an earlier rock formation
3. n. any entry into an area not previously occupied
4. n. entrance by force or without permission or welcome
5. n. entry to another's property without right or permission