1. Polyester fabric or clothing
   "She preferred natural fibers to poly"
    
2. A polyethylene bag
   "He packed his groceries in a poly"
    
3. [Brit, archaic, informal] A technical school offering instruction in many industrial arts and applied sciences
   "The poly offered a wide range of engineering programs";
   - polytechnic institute, polytechnic, engineering school

1. Many, multiple
   - multi-

Type of: tech [informal], technical school

Encyclopedia: Poly