WordWeb Online

1. Involving invasion or aggressive attack
   "invasive war";
   - incursive, invading
    
2. Gradually intrusive without right or permission
   "invasive tourists";
   - encroaching, trespassing
    
3. (medicine) relating to a technique in which the body is entered by puncture or incision
    
4. Marked by a tendency to spread especially into healthy tissue
   "invasive cancer cells"

See also: aggressive, fast-growing, intrusive, offensive, strong-growing

Antonym: confined, noninvasive

Encyclopedia: Invasive