perturb

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 […]

The Nobles ſtandyng by hearyng him thus ſpeake were greatly agreeued with him, notyng in him arrogancy and wilfulneſſe, in perturbyng and refuſyng ſuch an honeſt order of agreement: […]

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: […]

He remembered how, […] his childish imagination was perturbed at a phenomenon, for which he could not account.

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).

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.

To influence (a process or system) so that it deviates from its normal state.