per·turb
[per-turb]

verb (used with object)
1. to disturb or disquiet greatly in mind; agitate.

2. to throw into great disorder; derange.

3. Astronomy . to cause perturbation  in the orbit of (a celestial body).

Synonyms
1.  trouble. 2.  confuse, addle, muddle.

Antonyms
1.  pacify.