taking up the possession and management of property belonging to someone else; it can be legal, when someone is designated as an "intromettor with the goods and gear" of another, or illegal, when it is called "vicious intromission" in which case an heir intromits with the moveable property of his ancestors without right intrusion same idea as intromission, but has to do with heritable not moveable property; it means taking up possession of heritables without any title to do so