The Collaborative International Dictionary of English v.0.48:

Liege \Liege\ (l[=e]j), a. [OE. lige, lege, F. lige, LL. ligius,
   legius, liege, unlimited, complete, prob. of German origin;
   cf. G. ledig free from bonds and obstacles, MHG. ledec,
   ledic, lidic, freed, loosed, and Charta Ottonis de Benthem,
   ann. 1253, "ligius homo quod Teutonic[`e] dicitur ledigman,"
   i. e., uni soli homagio obligatus, free from all obligations
   to others; influenced by L. ligare to bind. G. ledig perh.
   orig. meant, free to go where one pleases, and is perh. akin
   to E. lead to conduct. Cf. Lead to guide.]
   1. Sovereign; independent; having authority or right to
      allegiance; as, a liege lord. --Chaucer.
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            She looked as grand as doomsday and as grave;
            And he, he reverenced his liege lady there.
                                                  --Tennyson.
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   2. serving an independent sovereign or master; bound by a
      feudal tenure; obliged to be faithful and loyal to a
      superior, as a vassal to his lord; faithful; loyal; as, a
      liege man; a liege subject.
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   3. (Old Law) Full; perfect; complete; pure. --Burrill.
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   Liege homage (Feudal Custom), that homage of one sovereign
      or prince to another which acknowledged an obligation of
      fealty and services.

   Liege poustie [L. legitima potestas] (Scots Law), perfect,
      i. e., legal, power; specif., having health requisite to
      do legal acts.

   Liege widowhood, perfect, i. e., pure, widowhood. [Obs.]
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Bouvier's Law Dictionary, Revised 6th Ed (1856):

LIEGE POUSTIE, Scotch law. The condition or state of a person who is in his
ordinary health and capacity, and not a minor, nor cognosced as an idiot or
madman, nor under interdiction. He is then said to be in liege poustie, or
in legitima potestati, and he has full power of disposal of his property. 1
Bell's Com. 85, 5th ed.; 6 Clark & Fin. 540. Vide Sui juris.