1. Hungry. Usually slightly hungry or simply wishing to give the impression of being slightly hungry. Derived from nip as in a small bite.
2. A little cold. The feeling of being cold but usually just a small amount mostly from a breeze and a lack of a jacket or coat. Thus not usually used to describe wearing multiple layers and still being a little cold. Derived from nippy.
1. I'm a little nippish, do you want to get some lunch? If not I'll be fine until dinner.
2. I'm kind of nippish, can I borrow your coat?