\Ly"ra\, n. [L. lyra, Gr. ?. See {Lyre}.]
1. (Astron.) A northern constellation, the Harp, containing a
   white star of the first magnitude, called Alpha Lyr[ae],
   or Vega.
2. (Anat.) The middle portion of the ventral surface of the
   fornix of the brain; -- so called from the arrangement of
   the lines with which it is marked in the human brain.