Used in the jocular phrase to give (Sc. take) leg-bail, to run away, decamp: see BAIL sb.1 5 c. Hence sometimes used (in allusion to this phrase) = unauthorized absence or departure, French leave, etc.
1774. Fergusson, Poems (1807), 234. They took leg-bail and ran awa Wi pith and speed.
1785. Grose, Dict. Vulg. Tongue, s.v. Leg, To give leg bail and land security, to run away.
1808. Sporting Mag., XXXII. 122. We have more occasion for leg-bail than they have.
1861. Hughes, Tom Brown at Oxf., xi. (1889), 107. [He] was giving them leg bail as hard as he could foot it.
1889. Century Mag., Feb., 632/1. Judgment was enforced by the scalping-knife, with leg-bail or a tribal warfare as a court of last resort.