Definitions
1.NounThe forcible inclusion or entry of an external group or individual; the act of intruding."She viewed sales calls as an unwelcome intrusion."
2.NounMagma forced into other rock formations; the rock formed when such magma solidifies.
3.NounA structure that lies within a historic district but is nonhistoric and irrelevant to the district.
4.NounThe insertion of a phoneme into the pronunciation of a word despite its absence from the spelling. (e.g. intrusive r)
5.NounAn involuntarily arising idea or memory that is nuisant and falsifies an accurate impression of the world.