adjective
skittish
SKIT-ish/ˈskɪtɪʃ/
Nervous and easily startled or unsettled.
The skittish cat recoils from a blowing leaf with one paw lifted.

Etymology
Skittish originally meant “very lively, frivolous.” Its later use for horses that were easily frightened and apt to run connects lively movement with the modern sense of nervousness or risk avoidance.
In context
Horses can be skittish if they're not familiar with things, can't they?
More examples
- Our skittish cat hides when visitors arrive.
- Investors grow skittish when stock prices fall sharply.
- After the accident, he feels skittish about driving at night.
Forms
skittish
skittishly adverb — In a nervous, easily startled manner.
skittishness noun — The tendency to become nervous or startled.
Similar words
- jumpy
- Especially suggests reacting nervously to sudden sounds or movements.
- nervous
- Describes anxiety generally, without necessarily suggesting readiness to startle.
- uneasy
- Suggests discomfort or worry rather than sudden startled reactions.