perturb

/pər-ˈtərb/

Middle English, from Middle French perturber, from Latin perturbare to throw into confusion, from per- + turbare to disturb

verb

  1. to cause to be worried or upset : disquiet, unsettle

  2. to throw into confusion : disorder

  3. to cause to experience a perturbation

Half way down the next flight, she smiled to think that a char-woman's stare should so perturb her.

discompose disquiet disturb perturb agitate upset fluster mean to destroy capacity for collected thought or decisive action. discompose implies some degree of loss of self-control or self-confidence especially through emotional stress. disquiet suggests loss of sense of security or peace of mind.