The Collaborative International Dictionary of English v.0.48:

Toga \To"ga\, n.; pl. E. Togas, L. Togae. [L., akin to
   tegere to cover. See Thatch.] (Rom. Antiq.)
   The loose outer garment worn by the ancient Romans,
   consisting of a single broad piece of woolen cloth of a shape
   approaching a semicircle. It was of undyed wool, except the
   border of the toga praetexta.
   [1913 Webster]

   Toga praetexta. [L.], a toga with a broad purple border,
      worn by children of both sexes, by magistrates, and by
      persons engaged in sacred rites.

   Toga virilis [L.], the manly gown; the common toga. This
      was assumed by Roman boys about the time of completing
      their fourteenth year.
      [1913 Webster]

WordNet (r) 3.0 (2006):

toga virilis
    n 1: (ancient Rome) a toga worn by a youth as a symbol of
         manhood and citizenship