Jamais

Au grand jamais = Never, no never.

Jambe

Il court à toutes jambes = He is running as fast as his legs will carry him.

[Compare: à toute bride, à toute vapeur, à toute vitesse.]

Il a pris ses jambes à son cou = He took to his heels.

Il a joué des jambes = He took to flight.

Il a des jambes de quinze ans = He still walks well.

Cela ne lui rend pas la jambe mieux faite! (ironic.) = And a lot of good that will do him!

Cela vous ferait une belle jambe (ironic.) = A fine lot of good that will do you.