The Collaborative International Dictionary of English v.0.48:

Trecento \Tre*cen"to\, n. & a. [It., three hundred, abbr. for
   thirteen hundred.]
   The fourteenth century, when applied to Italian art,
   literature, etc. It marks the period of Dante, Petrarch, and
   boccaccio in literature, and of Giotto in painting.
   [Webster 1913 Suppl.]