(Noun) A soft, mild, gentle wind or breeze.

In Context

“There was not even a zephyr stirring; the dead noonday heat had even stilled the songs of the birds; nature lay in a trance that was broken by no sound but the occasional far-off hammering of a woodpecker, and this seemed to render the pervading silence and sense of loneliness the more profound.”

Mark Twain, The Adventures of Tom Sawyer, 1876.