Similar to a Flex fit hat but as a T-shirt! Often worn trying to look stronger then you actually are. Derek fit T-shirts can be found in many kid sections but worn on grown ups.
Guy A:"Look at that guy over there! What is he wearing?"

Guy B:"Oh thats a Derek Fit shirt! Many people stop breathing but I guess they think it looks good."
by You WONT! February 24, 2011
Get the Derek Fit mug.