winterbourne

What it means

1. UKA stream that only flows in winter or after wet weather, particularly in an area rich in limestone.

   The stream is a winterbourne - it flows only in winter or other periods of high rainfall and is usually dry in summer.

   1980, AA Book of British Villages, Drive Publications Ltd, page 334, about Rockbourne

   1 more example

   [F]rom the graveyard itself burst up one of those noble springs known as winter-bournes in the chalk ranges, which, awakened in autumn from the abysses to which it had shrunk during the summer's drought, was hurrying down upon its six months' course, a broad sheet of oily silver, over a temporary channel of smooth green sward.

   1848, [Charles Kingsley], “The Philosophy of Fox-hunting”, in Yeast: A Problem. […], London: John W[illiam] Parker, […], published 1851, →OCLC, pages 14–15

In a sentence

[F]rom the graveyard itself burst up one of those noble springs known as winter-bournes in the chalk ranges, which, awakened in autumn from the abysses to which it had shrunk during the summer's drought, was hurrying down upon its six months' course, a broad sheet of oily silver, over a temporary channel of smooth green sward.

1848, [Charles Kingsley], “The Philosophy of Fox-hunting”, in Yeast: A Problem. […], London: John W[illiam] Parker, […], published 1851, →OCLC, pages 14–15

Where it comes from

1. Proto-Indo-European*bʰrewh₁-“to boil; to brew”
2. Proto-Germanic*wintruz
3. Old Englishwinterburna“stream that is full in winter”
4. Englishwinterbourne

From winter + bourne (“seasonal brook or stream”), partly also from the placenames Winterborne, Winterbourne, which are derived from Old English winterburna (“stream that is full in winter”), from winter (from Proto-Germanic *wintruz, further etymology uncertain) + burna (“stream”) (ultimately from Proto-Indo-European *bʰrewh₁- (“to boil; to brew”)). The Old English word appears to have survived only in placenames.