'knock-kneed' definitions:

Definition of 'knock-kneed'

(from WordNet)
adjective
Having the knees abnormally close together and the ankles wide apart

Definition of 'knock-kneed'

From: GCIDE
  • knock-kneed \knock"-kneed`\, a. Having the legs bent inward so that the knees touch in walking. [Written also knack-kneed.]