Under a spell and Weak-kneed

Weak-kneed and under a spell are semantically related. In some cases you can use "Weak-kneed" instead an adjective phrase "Under a spell".

Weak-kneed adjective - Lacking strength of will or character.

Under a spell and weak-kneed are semantically related. Sometimes you can use "Under a spell" instead an adjective phrase "Weak-kneed".