Jumpy \Jump"y\, a. [Compar. {Jumpier}; superl. {Jumpiest}.]
Jumping, or inducing to jump; characterized by jumps; hence,
extremely nervous; jittery.
Syn: edgy, fidgety, high-strung, in suspense(predicate),
jittery, nervous, nervy, overstrung, restive, uneasy,
uptight.
[Webster 1913 Suppl. WordNet 1.5]