Tumble-down and Weak knees

Tumble-down adjective - In deplorable condition.

Weak knees and tumble-down are semantically related. In some cases you can use "Weak knees" instead an adjective phrase "Tumble-down".

Tumble-down and weak knees are semantically related. Sometimes you can use "Tumble-down" instead an adjective phrase "Weak knees".