The wind was fair up the river, but foul for proceeding to the works by the lake.
The wind was fair up the river, and away we bowled before it.
You might have persuaded him to fist or cudgel, to a fair up and down, hand over, fight!
Old English fæger "beautiful, lovely, pleasant," from Proto-Germanic *fagraz (cf. Old Saxon fagar, Old Norse fagr, Old High German fagar "beautiful," Gothic fagrs "fit"), perhaps from PIE *pek- "to make pretty" (cf. Lithuanian puošiu "I decorate").
The meaning in reference to weather (c.1200) preserves the original sense (opposed to foul). Sense of "light-complexioned" (1550s) reflects tastes in beauty; sense of "free from bias" (mid-14c.) evolved from another early meaning, "morally pure, unblemished" (late 12c.). The sporting senses (fair ball, fair catch etc.) began in 1856. Fair play is from 1590s; fair and square is from c.1600. Fair-haired in the figurative sense of "darling, favorite" is from 1909. First record of fair-weather friends is from 1736.
early 14c., from Anglo-French feyre (late 13c.), from Old French feire, from Vulgar Latin *feria "holiday, market fair," from Latin feriae "religious festivals, holidays," related to festus "solemn, festive, joyous" (see feast).