intrusion

noun9

1. •
   The forcible inclusion or entry of an external group or individual; the act of intruding.

   • She viewed sales calls as an unwelcome intrusion.
2. •
   A penetration by hackers, a computer virus, etc.

   • The intrusion of the virus rendered our other security efforts useless.
3. •
   The insertion of a phoneme into the pronunciation of a word despite its absence from the spelling. (e.g. intrusive r)

   • A current challenge in recent work on Spanish sound structure is to understand the conditions that determine vowel intrusion and the consequences vowel intrusion may have on Spanish phonology. — 2009
4. •
   Something that is intrusive or that has arisen from an act of intruding.
5. •
   Magma forced into other rock formations; the rock formed when such magma solidifies.
6. •
   A structure that lies within a historic district but is nonhistoric and irrelevant to the district.

   • This setting is slightly altered by modern intrusion. — 1969
7. •
   An involuntarily arising idea or memory that is nuisant and falsifies an accurate impression of the world.

   • Intrusion symptoms (e.g., nightmares) and anhedonia symptoms were associated with significantly lower probability of reporting moderate physical activity. — 2024
8. •
   (rare) A swarm or nest of cockroaches, infesting a structure.

   • When I turned on the light, scattered mats of cockroach intrusions scurried into the walls.
   • The sight of an intrusion had me running for an exterminator.
9. •
   A feeling of being intruded upon; the state or condition of being intruded.

   • I watched and felt intrusion upon the reigning terror of them — 2021