perturb

verb6

1. •
   To cause (something) to be physically disordered or disturbed; to cause confusion.

   • Mary therefore the more knaue art thou I say / That perturbest the worde of god I say […] — 1521
2. •
   To disturb (someone, their mind, etc.) mentally; to bother, trouble, upset.

   • […] I have often found / The truth thereof, in my private passions: / For I doe never feele my selfe perturb'd / VVith any generall vvords 'gainst my profession, / They doe avvake, and stirre me: […] — 1632
3. •
   To bother, to disturb, to trouble.

   • Thy ghost O father sweete, thy greuous ghost, / Perturbing in my dremes hath me compeld to see this coast. — 1557
4. •
   Of a celestial body: to modify the motion or orbit of (another celestial body) by exerting a gravitational force; hence (physics), to slightly modify (the motion of an object).
5. •
   To slightly modify (a set of equations or their solutions), producing deviations from a simple, easily solvable problem, in order to find an approximate solution to a problem that is more difficult to solve or otherwise unsolvable.
6. •
   To influence (a process or system) so that it deviates from its normal state.