Gait is how someone walks; a gate is something you open and close. Remember that gait has an i, like the i in walking, while gate is the spelling for the physical thing you swing open and shut.
The core difference
Gait is a manner of walking or moving, while a gate is a barrier or an entrance point.
- gait — a person's or animal's manner of walking or moving: The injury gave her an uneven gait.
- gate — a movable barrier in a wall or fence: She latched the garden gate behind her.
- gate — the boarding area at an airport: Our flight is boarding at gate 22.
How to tell them apart
Gait is about movement: a limp, a stride, or the walk, trot, canter and gallop of a horse. Gate is a physical object or place. A quick check is to ask whether you could walk through it. If so, it is a gate; if it describes how you walk, it is gait.
The mix-up shows up when writing about health and horses, where people write an unsteady gate instead of an unsteady gait. The two words are related in history, since gait comes from an old use of gate meaning way or manner, but today they are kept firmly apart.