A Frush is a crush on a friend that is attracted to a sexually that you are not attracted to.
"I have a Frush on Jessica"
A friend crush.
Someone you want to be your friend
Hey that girl Emily is so frushing on you!
I totally have a frush on Jack!
Used to describe an experience where a huge "rush" of energy or excitement comes over you causing you to fart.
Harvey: STANKY dawg, did you just frush??
Frankle: Dude I'm sorry, that babe is just too hot!!