look up any word, like dirty sanchez:
 
1.
Don't Fuck It Up
ok guys, NASA needs this part to be Top secret with no Flaws, DFIU
by Security man of the century May 08, 2011
 
2.
Dont Fuck It Up
before embarking on any important task or activity a chant of DFIU (pronounced dee phi you) would usually be heard among participants
by a_girl_called_toby April 19, 2009