1. A superficial or slight understanding of something or "piecemeal knowledge"; a smidgen: Lee knows only a smattering of the local language despite the fact that he has lived there for several years.
2. A small amount or number; a touch or a trace: Although the spring weather has been very pleasant, there has been only a smattering of the much needed rain for the fruit trees and crops.

The speaker received a smattering of applause from the audience; especially, since he obviously didn't know what he was talking about.