Capable of being mentally or emotionally disturbed; easily excited or made anxious. Now somewhat rare.

That winces; †restive (literal and figurative); recoiling, flinching.

Of a person or temperament: excitable, highly strung, easily agitated, anxious, timid; hypersensitive; worried, anxious (about); afraid…

designating or having a nervous and sanguine temperament.

Easily frightened, disturbed, or startled.

Of a person. Feeling, or susceptible to, intense emotion or affection. Also, manifesting intense emotion or excitability, esp. in aesthetic or…

figurative. In a state of nervous or mental strain or tension; strained; highly strung; ‘on the stretch’; excited, or excitable; keenly sensitive.

In the sense of string, v. 3. With prefixed adverb, finely-strung, highly strung adj. at highly, adv. compounds: said of persons with reference to…

That may be fluttered.

Easily shocked. Also absol. in plural sense (with the).