An arbour is a shelter in a garden made by growing plants over a frame, often shaped like an arch. Roses, grapes, or other vines climb it and become the roof, or a big part of the roof. People sit in the shade. It is not a wooden hut with a solid top. Americans usually spell the same garden word arbor. Though actually, the word did not start from “tree.” In Middle English it was a changed form of herber or erber, a pleasure garden or herb garden; later the spelling was pulled toward Latin arbor, “tree.” So it looks like a tree-word now, and the thing itself is often covered in climbing plants, but that tree-look in the letters is a later twist. Do not mix it up with harbour, the place for ships; they only look like cousins.

涼亭；花架（藤蔓棚架）。英式拼法；美式寫 arbor。不是停船的 harbour。