Generic term to classify and insult anyone who either enjoy's 'extreme sports', rock music, metal music, alternative music, goth music, industrial music etc...
Stereotypical 'Greebo' would listen to Nu-Metal and wear loose fitting jeans.
Term is generally used by a Towny as an insult. Stereotypical Towny would listen to Garage music and wear branded sportswear - prefferably Nike Reebok or Adidas, Reebok Classic Training shoes, Baseball cap - either navy blue or white.
Towny see also: kevtownychav
Towny: Oi, you iz a greebo innit? or iz you a goff? Iz all da same innit.
Greebo: Don't fart or you might blow your classics off.