/in vay"siv/ , adj.
1. characterized by or involving invasion; offensive: invasive war.
2. invading, or tending to invade; intrusive.
3. Med. requiring the entry of a needle, catheter, or other instrument into a part of the body, esp. in a diagnostic procedure, as a biopsy.
[ 1400-50; late ME invasivus. See INVASION, -IVE ]