A quay is a landing place built on the edge of a body of water, used primarily to load and unload items and people onto and from vessels. The plural is quays. It is only capitalized when it is part of a proper name.
It is more commonly used outside of the United States, which prefers the term dock.
The derivative quayage is the payment a customer would give to use a quay.
This word can be pronounced three different ways (e.g., key, kay, and kway). Because of this, it may have a homonym of key, which has many meanings including a reef or island, especially in the Caribbean. The state of Florida has an area dubbed the Florida Keys, or a series of islands.
Examples
Phillip Holliday, Border Force regional director, said: “These smugglers thought that because they were operating at night and targeting a small quay their offences would go undetected. They were wrong.” [BBC]
In March The Sunday Times was alerted to the discovery of sizeable wooden beams by workers concerned about the lack of protocols around heritage on the $2.6 billion Elizabeth Quay project. [Perth Now]
People had been seen swimming between the town and port quays and there was some confusion as to whether all the people reported in the water had been accounted for. [Daily Echo]
From all quarters, without equivocation, even if it requires an equestrian route and payment of quayage, quiet your quarreling, quit your inquietudes, and acquiesce to the quizzical inquiry into this unique and unequivocally quirky custom: Q and U have exquisitely quantified their quizzotical and quid-pro-quo correlation to become a couple. [Vinton Today]