Having the knees abnormally close together, and the ankles spread apart(adjective)
Suffering from genu valgum (or tibia valga)(adjective)
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Use "knockkneed" in a sentence
"The last time I had let myself go so completely was with Tim, which still left me knockkneed in my own kitchen six years later, as I had discovered tonight."
"The door crashed open and the piano player made his ridiculous, knockkneed run for the sun."
"When the old farmer went up to him with knockkneed, rheumatic tread, inquiring, "Well, how goes it?" the architect would reply:"