A teenager who is pre-occupied with trivial things such as material posessions, celebrities, the opposite sex, and current fads and fashions. They usually have a low literacy rate, and little to no self-respect or respect of others. They may or may not smoke, and many feti remain feti long into adulthood.
"Good god, I went on a date with this feti, and he wanted for me to give him head! What a feti thing to do!"
"That girl over there, the one with the fake-tan, bleached hair, and velour tracksuit, looks like a complete feti!"