JUNE is a 4 letter word that starts with J.

1. \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.
   
   

2. \Ju"ne\, n.; pl. {Junos}. [L.]
   1. (Rom. Myth.) The sister and wife of Jupiter, the queen of
      heaven, and the goddess who presided over marriage. She
      corresponds to the Greek Hera.
   
            Sweeter than the lids of Juno's eyes. -- Shak.
   
   2. (Astron.) One of the early discovered asteroids.
   
   {Bird of June}, the peacock.