noun; southern US slang. meaning "small pants", often referring to a child, sometimes a child of a particularly gregarious and cute nature who adults may have the inclination to beat, but can't because of the extreme level of cuteness.
Mom- "Darn it!, who let the puppy get into the honey favored cake batter?"
Grandmother- "Ohhhhh, leave her be. It's just Mary. In fact you were quite the snickle britches when you were that age."