Synonyms for perturb

Most common

1. Disturb — to disturb (someone, their mind, etc.) mentally; to bother, trouble, upset

2. Unsettle — to cause (something) to be physically disordered or disturbed; to cause confusion

3. Disquiet

disquiet, disorder, distract, trouble, unhinge, cark dated

v. 1
To cause (something) to be physically disordered or disturbed; to cause confusion.
v. 2
To disturb (someone, their mind, etc.) mentally; to bother, trouble, upset.
v. 3
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).

Past participle: perturbed
e.g. perturbed → disturbed, agitated, bothered, ruffled…

Use in printed books, per decade from 1850 to 2019.

3 letters: vex¹
4 letters: stir¹, toss¹, fret¹, rile¹, roil¹, cark
5 letters: throw¹, upset², annoy², addle²
6 letters: bother², puzzle², harass², excite², flurry², dazzle², ruffle², muddle², jumble², fuddle²
7 letters: trouble², confuse², disturb², provoke², agitate³, perplex², mortify³, fluster², unhinge², embroil², derange², flummox²
8 letters: disorder³, distress², distract², disquiet³, unsettle³, entangle³, convulse, bewilder³, befuddle³
9 letters: aggravate³
10 letters: disconcert³, discompose
11 letters: enturbulate

The small number after each word is its number of syllables (upset² = 2 syllables).