From Longman Business Dictionarypollution creditpolˈlution ˌcredit [countable, uncountable]TAX a form of tax credit that a company which does not cause much POLLUTION (=damage to the environment) can sell to one that does. The system is intended to decrease the general level of pollutionPlants whose emissions are well below the permitted level can sell pollution credits to units which find cleaning up more difficult. → credit