intrusive

Tending to intrude; doing that which is not welcome; interrupting or disturbing; entering without permission or welcome.

Geography, Geology, Natural sciences Of rocks: forced, while in a plastic or molten state, into the cavities or between the cracks or layers of other rocks.

Human sciences, Linguistics, Sciences epenthetic

Computing, Engineering, Mathematics, Natural sciences, Physical sciences, Programming, Sciences Designating a type of collection in which each item keeps track of what collection it is in, rather than the more conventional approach of a collection keeping track of what items it contains. An intrusive collection does not "own" its contents and a single item can be part of multiple intrusive collections.