gray market (or grey market)

Includes products with legitimate, authorized trademarks that are intended for sale and use outside the United States, but which are imported and sold in the United States without the consent of the U.S. trademark owner or authorized distributor of like domestic goods.

Protecting the Brand: Counterfeiting & Gray Markets (Hlavnicka, Keats, & Drimalla 2013)

For further reference, see the December 2016 article from The Brand Protection Professional.