Kung Fu, 功夫 Gōngfū - Means “effort” “hard Work”
This phrase 練拳不練功, 到老一場空 (Liàn quán bù liàngōng, dào lǎo yīchǎngkōng). Basically means if you train Kung Fu without training internal, you end with nothing in old age.
Does not change the translation of Kung Fu to what you originally stated
You disagree with my translation of kung fu? Not sure how to process that one I can explain it if you want, but really, such a small thing.