skeg

The word "skeg" began as a nautical term and is still used mainly for parts of boats and similar craft. In the classic sense, it is an extension at the rear of the keel, or a lower support near the rudder, that helps protect steering parts and helps the craft move straight through the water. On small boats, outboard motors, and other watercraft, the word can also refer to a similar protective projection underneath.

The term was later used in surfing, kayaking, and related water sports. In that setting, a skeg is the fin on the underside of a surfboard, paddleboard, or kayak. It improves tracking and stability by reducing sideways slip, which makes the craft easier to control. This is now one of the most familiar everyday uses of the word.

Beyond water use, "skeg" also appears in some British dialects as a noun meaning a look or glance, especially in phrases like "have a skeg." That meaning is real but regional, so learners are far more likely to meet the word in boating or board-sports contexts. The word goes back to Old Norse skegg, "beard," probably because the original nautical part looked like a beard-like projection. In modern English, though, the main idea is simple: it is usually a stabilizing or protective part under a craft, and only sometimes a regional word for a quick look.