From Longman Business Dictionaryaftermarketaf‧ter‧mar‧ket /ˈɑːftəˌmɑːkətˈæftərˌmɑːr-/ noun [countable] British English1FINANCE the period of trading immediately after a new bond, share etc is ISSUED (=first sold), when its future price is still uncertainThe stock issue traded at a premium in the aftermarket.2MARKETING the market for products that people buy after they have bought another related product, for example spare parts or extra pieces of equipmentthe large US aftermarket for replacement car parts
