(1) “Claimant” includes any individual, firm, partnership, association or corporation.

(2) “Contracting body” means any officer, employe, authority, board, bureau, commission, department, agency or institution of the Commonwealth of Pennsylvania or any State-aided institution, or any county, city, district, municipal corporation, municipality, municipal authority, political subdivision, school district, educational institution, borough, incorporated town, township, poor district, county institution district, other incorporated district or other public instrumentality, which has authority to contract for the construction, reconstruction, alteration or repair of any public building or other public work or public improvement, including highway work.

(3) “State-aided institution” shall mean and include any institution which receives State funds directly or indirectly for the construction, reconstruction, alteration or repair of its buildings, works or improvements, including highway work.