The following words and phrases when used in this chapter shall have the meanings given to them in this section unless the context clearly indicates otherwise:
"Local government unit." A county, city, borough, incorporated town, township, school district, vocational school district, county institution district, home rule municipality, local authority or any joint or cooperative body of local government units or any instrumentality, authority or corporation thereof which has authority to enter into a contract.
62 Pa.C.S. § 4602