lavant

noun2

1. •
   (dialect, UK) A shallow or more or less intermittent spring, or the stream of water (bourne) which feeds and springs forth from such a spring.

   • In this part of Hampshire a bourn is called a lavant, and after long internals when a lavant rises at Hambledon, some of the springs rise from, or quite close to[,] the churchyard itself. — 1891
2. •
   (dialect, UK) A violent flow or rush of water.

   • How it did rain! It ran down the street in a lavant.