The Collaborative International Dictionary of English v.0.48:

Praetexta \Pr[ae]*tex"ta\, n.; pl. Pr[ae]text[ae], E.
   Pr[ae]textas. [L. (sc. toga), fr. praetextus, p. p. of
   praetexere to weave before, to fringe, border; prae before +
   texere to weave.] (Rom. Antiq.)
   A white robe with a purple border, worn by a Roman boy before
   he was entitled to wear the toga virilis, or until about the
   completion of his fourteenth year, and by girls until their
   marriage. It was also worn by magistrates and priests.
   [1913 Webster]