skittish

/ˈskɪtɪʃ/
adjective
  1. (Of an animal, especially a horse) easily frightened or startled; nervous.
    • Our dog is skittish around strangers and hides under the bed.
    • The skittish mare shied away from the loud noise of the tractor.
    • Skittish deer will bolt if they catch a human scent.
  2. (Of a person) nervous, excitable, or unpredictable in behavior or mood.
    • The actor was skittish before the live performance, pacing backstage.
    • He grew skittish whenever the topic of marriage came up.
    • Investors became skittish after the stock market dropped sharply.
  3. Tending to change one's mind or be unreliable; fickle.
    • His skittish voting record made it hard to predict his stance.
    • She's skittish about committing to a long-term plan.
    • The skittish weather kept switching from sun to rain all day.
Antonyms