Wiktionary
alt. A cirrus cloud formation resembling horse tails. n. A cirrus cloud formation resembling horse tails.
Usage examples of "mares' tails".
It did not help that the weather was changing, long mares' tails wisping orange in the highest part of the sky, wind gusting up, air damp&mdash.
Cold as ice, and the stars frozen like icicles fading to the dawn sky - pale blue and full of mares' tails.
The sky in the east was a rich predawn Prussian blue, with high cirrus clouds already catching the light, like pink mares' tails.
There are the transient tumbled clouds, the windy wisps of mares' tails, the crackling mackerel skies and the romping delightful tumult of the thunderstorms.
Mountains, not green but blue, were still streaked with snow at the summits, and long mares' tails of water cascaded over the rocky faces in tumbles and falls tracing through stone and forest for thousands of feet.