Source : Webster's Revised Unabridged Dictionary (1913)

June \June\, n. [L. Junius: cf. F. Juin. So called either from
   Junius, the name of a Roman gens, or from Juno, the goddess.]
   The sixth month of the year, containing thirty days.

         And what is so rare as a day in June? Then, if ever,
         come perfect days.                       -- Lowell.

   {June beetle}, {June bug} (Zo["o]l.), any one of several
      species of large brown beetles of the genus {Lachnosterna}
      and related genera; -- so called because they begin to
      fly, in the northern United States, about the first of
      June. The larv[ae] of the June beetles live under ground,
      and feed upon the roots of grasses and other plants.
      Called also {May bug} or {May beetle}.

   {June grass} (Bot.), a New England name for Kentucky blue
      grass. See {Blue glass}, and Illustration in Appendix.

Poa \Po"a\, n. [NL., fr. Gr. ? grass.] (Bot.)
   A genus of grasses, including a great number of species, as
   the kinds called {meadow grass}, {Kentucky blue grass}, {June
   grass}, and {spear grass} (which see).

Source : WordNet®

June grass
     n : valuable meadow and pasture grass in Europe and especially
         central United States having tall stalks and slender
         bright green leaves; a chief constituent in lawn grass
         mixtures [syn: {Kentucky bluegrass}, {Kentucky blue}, {Kentucy
         blue grass}, {Poa pratensis}]