The fashion or commonly worn drab of fraternity members. It is not uncommon to see pledges adopt the style very quickly in order to distinguish themselves from the local population and to seek acceptance from the membership.
Some common examples of traditional frattire are Vineyard Vines, Polo (sweaters, hats, shirts), Northface/Mountain Hardware jackets, Sperry shoes.
1.I heard Vineyard Vines is posting up some sick sales on their frattire!
2. Nice frattire! I haven't seen a Polo in that shade of blue, yet!