A plant is potbound when its roots have filled up the whole pot and have nowhere left to go. The roots go round and round the inside of the pot, packed together, sometimes coming out of the hole at the bottom. Once that happens the plant cannot take in enough water or food, so the leaves go yellow, growth stops, and the soil dries out almost as soon as you water it. The cure is simple: move the plant to a bigger pot, and loosen the tangled roots a little first. This is a gardener's word. You meet it on plant labels, in gardening books, in a shop when someone tells you why your plant is not doing well. It is an adjective and usually comes after 'be' or 'get': the plant is potbound, it has got potbound. You will hear 'root-bound' just as often, and in American gardening more often; the two words mean the same thing. English speakers do sometimes stretch it to people — a person stuck in a job or a small town with no room left to grow can be described as potbound. That is a comparison, not a normal use, and you should recognise it rather than reach for it yourself. Spelling: potbound or pot-bound, both used.

盤根的、根長滿盆的（園藝說法，就是該換盆了）