What does "intrusion" mean?

Intrusion: (Geol.) The penetrating of one rock, while in a plastic or metal state, into the cavities of another.

Additional senses

  1. 2.(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.
  2. 3.(Scotch Ch.) The settlement of a minister over 3 congregation without their consent.

Sources