Excitable (adjective)

1. Likely to become easily excited or emotionally aroused.
2. Easily excited or stimulated.

Origin:

Early 17th century (in the sense "capable of being excited"): from late latin excitabilis, from the verb excitare (see excite).

Examples:

1. The dog is excitable and jumps around when it sees its owner.
2. The crowd was excitable and cheered loudly at the concert.
3. The excitable child could not sit still.
4. The excitable horse was hard to control.
5. The excitable students were eager to learn.