On the windy side
[to Hero] Lady, as you are mine, I am yours; I give away
myself for you and dote upon the exchange.
Speak, cousin, or (if you cannot) stop his mouth with a kiss,
and let not him speak neither.
In faith, lady, you have a merry heart.
Beatrice:Much Ado About Nothing Act 2, scene 1, 308–315
Yea, my lord, I thank it, poor fool, it keeps on the windy
side of care.
After Shakespeare's usual dose of anxiety and suspicion, the young and inexperienced Claudio is affianced to the young and inexperienced Hero. Hero's witty cousin Beatrice pokes a little fun at the timid bride-to-be, urging her either to say something or to "stop" Claudio's mouth—that is, kiss him. Pedro comments on Beatrice's merriness, which is noteworthy since she claims to despise the very idea of marriage [see VALIANT DUST]. Her heart, she replies, is like a "poor fool," who, to earn his keep, must keep on "the windy side of care." There is some disagreement as to where this image comes from, although critics and editors agree that "the windy side of care" means something like "out of care's way." A glum fool is an unemployed fool.
The phrase may derive, as the editor A. R. Humphries suggests, from a nautical image, so that to be on the "windy side" means to be to the windward of care and therefore to intercept the wind and steal it from care's sails. The OED guesses that the phrase means to be situated windward so as "not to be 'scented' and attacked" by care. Though both these derivations seem a little forced, I can suggest nothing better.
In a later comedy, Twelfth Night, Fabian approves a scurrilous and provocative letter that Sir Andrew Aguecheek has written to a supposed competitor in love. Sarcastically, Fabian tells Sir Andrew that "Still you keep o'th' windy side of the law" (Act 3, scene 4)—that is, he pulls back from the verge of slander, which might land him in court.