Verb
plead the fifth (third-person singular simple present pleads the fifth, present participle pleading the fifth, simple past pled the fifth or pleaded the fifth, past participle pled the fifth)
Alternative spelling of plead the Fifth (both senses)
(law, US) To invoke the Fifth Amendment to the United States Constitution, which protects witnesses from being forced to incriminate themselves.
(informal) To refuse to answer a question, or refuse to speak, especially when the response would reflect badly on the speaker.
Source: en.wiktionary.orgAppearing on Andy Cohen's Watch What Happens Live and during a game called Plead The Fifth, he was asked to reveal which of the five band members was the most well-endowed. Source: Internet