PERTURBATE
Per"tur*bate, a.

Defn: Perturbed; agitated. [R.]

PERTURBATION
Per`tur*ba"tion, n. Etym: [L. perturbatio: cf. F. perturbation.]

1. The act of perturbing, or the state of being perturbed; esp., agitation of mind.

2. (Astron.)

Defn: A disturbance in the regular elliptic or other motion of a heavenly body, produced by some force additional to that which causes its regular motion; as, the perturbations of the planets are caused by their attraction on each other. Newcomb.

PERTURBATIONAL
Per`tur*ba"tion*al, a.

Defn: Of or pertaining to perturbation, esp. to the perturbations of the planets. "The perturbational theory." Sir J. Herschel.

PERTURBATIVE
Per"tur*ba*tive, a.

Defn: Tending to cause perturbation; disturbing. Sir J. Herschel.