Ferdeff 

Usually a name used as a substitute for "fersure".

"cooler then the hannah montana cake at your party?"
"Yes. ferdeff."

Ferdeff by Ashamish January 11, 2008

Ferdef 

Abbreviated slang term for "definetely"

Similar to the usage "fosho"

Are you gonna hit up that party?
Ferdef!

Ferdef by jtmo September 25, 2008

Ferdef 

For definitely. Another option for, fer sure, and fo sho.

I am ferdef going to that show next week.

Ferdef by w007! August 5, 2008