Definitions of passing off
(INTELLECTUAL PROPERTY) a deceptive (=misleading) market practice, often involving trademarks, that causes a company's products or services to be confused with those of a competitor
Innotech opposed the registration of the trade mark on the grounds of passing off.
the action of pretending that one thing is another thing in order to cheat a customer or client
He appears to be passing off copy-pasted text from another writer's work as an exclusive interview.