perturbs

/P ER0 T ER1 B Z/
verb
  1. 1

    To disturb; to bother or unsettle.

  2. 2

    To slightly modify the motion of an object.

  3. 3

    To modify the motion of a body by exerting a gravitational force.

  4. 4

    To modify slightly, such as an equation or value.

Source: https://en.wiktionary.org/wiki/perturb, https://en.wiktionary.org/wiki/perturbs