Source : Webster's Revised Unabridged Dictionary (1913)

Leger \Leg"er\, a. [F. l['e]ger, fr. LL. (assumed) leviarius,
   fr. L. levis light in weight. See {Levity}.]
   Light; slender; slim; trivial. [Obs. except in special
   phrases.] --Bacon.

   {Leger line} (Mus.), a line added above or below the staff to
      extend its compass; -- called also {added line}.

Source : WordNet®

leger line
     n : a short line; a notation for extending the range above or
         below the staff [syn: {ledger line}]