Common slang in Pittsburgh. Means to be "nosey", poking into other people's business. It's derived from Old English neb, a bird's beak. Related to nib, the fountain pen tip that's shaped like a bird's beak. To be nebby is to be continuously poking around, exploring, as a bird does. Related Pittsburghese includes neb-nose and neb-shit.
by rubyrichard September 17, 2015