Who uses it: Sailors
What it means: The side-slippage of a boat downwind (leeward). Leeway happens because water and wind push rudders, keels and centerboards; you can turn the rudder to point the boat the way you want to go, but you have to adjust for leeway. Different boats have different, but predictable, amounts of leeway.
How to use it: To excuse deviation from your intended course.
Thanks to my dad for suggesting this term, which has become a common expression even though most people have no idea what it refers to. (Other sailing terms in daily use: taking a different tack, sailing too close to the wind, jury rig... you'll see a lot of these over the next 11 months.)
People use "leeway" to give themselves some slack (another sailing term), but if you're serious about plotting your course, you include a specific amount of leeway in your calculations. In the days before LORAN and GPS, even a single degree's miscalculation could send a boat miles off course, so you needed to know exactly how much leeway you had.
Now, of course, even cars have GPS, which takes a little adventure out of life. Assuming you know how to use the GPS, that is. My Uncle Ziggy has a brand-new handheld GPS he was using this past weekend, and when he and my Aunt Debbie arrived late to dinner, the rest of us made some ungenerous and probably unfair remarks about the new toy. Sorry about that... you know we're all just jealous.
Another summer has come and gone, and I never did get out on the water this year, except briefly in a kayak off Martha's Vineyard last month. This morning Dizzy and I walked down to Gardiner Landing, where they'll be taking the floating docks in soon. Maybe next year I'll get a boat of my own.