lavant
A shallow or more or less intermittent spring, or the stream of water (bourne) which feeds and springs forth from such a spring.
Lavants, are land springs, which break out much, on the downs of Sussex, Hants, and Wilts. The country people say, that when the Lavants rise, corn will be dear; meaning, that when the earth is so glutted with water as to send[…]
A violent flow or rush of water.
How it did rain! It ran down the street in a lavant.
Where it comes from
Uncertain. Possibly from Middle English *lavand, *lavant, lavande, present participle of Middle English laven (“to stream, pour out a stream, wash”), from Old English lafian (“to pour water on, wash, lave, bathe, ladle out”), equivalent to lave + -and; or from Old French lavant, present participle of laver (“to wash”). See lave.
Adapted from the Wiktionary entry lavant (CC BY-SA 4.0).