From The Collaborative International Dictionary of English v.0.48:
Lyra \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.
[1913 Webster]
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.
[1913 Webster]