A quay is a place in a town or harbour where boats can tie up, stop, and load or unload goods. It is usually a solid platform of stone or concrete along the water, with ships lying beside it. In British English this is a normal word; you will see it on maps and street names. American English often says dock, pier, or wharf, though quay is understood. Though actually, a pier more often sticks out into the water, and a quay more often runs along the shore — people mix these when they talk loosely. The spelling looks as if it should sound like “kway,” but it is pronounced like key. English used to spell it key; in the 1690s they changed the spelling to look like French quai, without (at first) changing how they said it. So quay and the key that opens a door are different words that happen to sound the same.