Final answer:
In the context of the exhibit on Shakespeare, 'notorious forgeries' refers to infamous and deceptive imitations of original works that are known for their falseness and deceptive nature.
Step-by-step explanation:
The phrase 'notorious forgeries' in the given context refers to infamous works that are created to imitate something original, but with the intent to deceive. These works have garnered a reputation for being known more for their falseness rather than their craft or artistry. They are not simple imitations or honorable mentions; rather, they are infamous because their creation involves a deceitful claim to authenticity that has been exposed and publicly criticized.