Webster's Revised Unabridged Dictionary · 1913

Perturb

Perturb , transitive verb

[Latin perturbare, perturbatum; per + turbare to disturb, from turba a disorder: compare Old French perturber. See Per-, and Turbid.]

1.
To disturb; to agitate; to vex; to trouble; to disquiet.
Ye that... perturb so my feast with crying. — Chaucer
2.
To disorder; to confuse. [Rare] — Sir T. Browne