A spunky person is someone who's high spirited and brave. The hero of a fairy tale is often described as spunky.
It takes a spunky traveler to cheerfully find her way across a busy city without a map, and a spunky kindergartner might march bravely into school on the first day. Someone who's spunky isn't just courageous — there's an implied pep or eagerness to the word as well. The word spunky comes from the 1530's Scottish meaning of spunk, "a spark," which is rooted in the Gaelic word spong, "tinder, pith, or sponge."