From Longman Dictionary of Contemporary Englishinvasivein‧va‧sive /ɪnˈveɪsɪv/ adjective 1 MHinvasive medical treatment involves cutting into someone’s body invasive surgery2 an invasive disease spreads quickly and is difficult to stop invasive bladder cancers3 an invasive plant spreads quickly in a garden or other area, so that it becomes a problem