WordWeb Online

1. Increase in extent or intensity
   "The Allies intensified the bombing";
   - escalate, step up
    
2. Make more intense, stronger, or more marked
   "The efforts were intensified"; "Her rudeness intensified his dislike for her";
   - compound, heighten, deepen
    
3. Become more intense
   "The debate intensified";
   - deepen
    
4. (photography) make the chemically affected part of (a negative) denser or more opaque in order produce a stronger contrast between light and dark

Derived forms: intensified, intensifies, intensifying

Type of: alter, change, increase, modify