What does "pithy" mean?

Pithy: Having nervous energy; forceful; cogent. This pithy speech prevailed, and all agreed. Dryden. In all these Goodman Fact was very short, but pithy. Addison. Pithy gall (Zoöl.), a large, rough, furrowed, oblong gall, formed on blackberry canes by a small gallfly (Diastrophus nebulosus).