say it: in-TROO-zhuhn
intrusion is a noun meaning "any entry into an area not previously occupied". It carries 5 recorded senses.
any entry into an area not previously occupied
“an invasion of tourists”
“an invasion of locusts”
entrance by force or without permission or welcome
the forcing of molten rock into fissures or between strata of an earlier rock formation
rock produced by an intrusive process
entry to another's property without right or permission
Forms marked · are formed by the regular rule rather than recorded in the source data. English keeps a few hundred irregulars and the rest follow the pattern, so the rule is right far more often than not — but it is a rule, and the mark says so.
Definitions, synonyms and semantic relations for intrusion come from Princeton University’s WordNet. The pronunciation comes from the CMU Pronouncing Dictionary. Commonness is measured against a corpus of everyday English. Full sources and licences.