invasive has 4 distinct synonyms spread across 2 of its 4 senses. Each sense below keeps its own list, because a synonym belongs to a meaning and not to a word: swapping one sense's substitute into another sense's sentence is how a thesaurus makes writing worse. Its 2 recorded opposites are noninvasive, confined.
Counts are distinct word forms across every sense. A synonym that appears under three senses is counted once here and shown three times below, under each sense it belongs to.
relating to a technique in which the body is entered by puncture or incision
marked by a tendency to spread especially into healthy tissue
“invasive cancer cells”
gradually intrusive without right or permission
“we moved back from the encroaching tide”
Synonyms, antonyms and the broader and narrower relations for invasive come from Princeton University’s WordNet. Full sources and licences.