bow leg vs genu varum

bow leg and genu varum both are nouns.

Word	Noun	Adjective	Verb	Adverb
bow leg	Yes	No	No	No
genu varum	Yes	No	No	No

As nouns, bow leg and genu varum are synonyms defined as:

bow leg and genu varum: a leg bowed outward at the knee (or below the knee)

Other synonyms of bow leg include bandy leg, bandyleg, bowleg, tibia vara.

bow leg (noun)	genu varum (noun)
a leg bowed outward at the knee (or below the knee)	a leg bowed outward at the knee (or below the knee)
outward curvature of the legs