noun
grey market; gray market
Refers to the trade of goods through unofficial or unauthorized channels, often parallel importing or selling outside authorized distribution networks.
グレーマーケットで買ったスマホは保証が効かないことがある。
Smartphones bought on the grey market may not be covered by warranty.
そのカメラはグレーマーケット品だから、正規
That camera is a grey market item, so it's cheaper than the official product.