take/plead the fifth

take the Fifth

Refuse to answer on the grounds that one may incriminate oneself, as in He took the Fifth on so many of the prosecutor's questions that we're sure he's guilty. This idiom refers to the Fifth Amendment to the U.S. Constitution, which states that no person shall be compelled to be a witness against himself or herself. [Mid-1900s]
See also: fifth, take

take the fifth

(in the USA) exercise the right of refusing to answer questions in order to avoid incriminating yourself.
The reference in this phrase is to Article V of the ten original amendments ( 1791 ) to the Constitution of the United States, which states that ‘no person…shall be compelled in any criminal case to be a witness against himself’.
See also: fifth, take

take/plead the ˈfifth

(American English) make use of the right to refuse to answer questions in court about a crime, because you may give information which will make it seem that you are guiltyFrom the Fifth Amendment of the US Constitution, which guarantees this right.
See also: fifth, plead, take

take the fifth

1. and five it tv. to refuse to testify to a U.S. legislative committee under the protection of the Fifth Amendment to the U.S. Constitution. The lawyer just sat there and said, “Five it” after every question.
2. tv. to decline to answer any questions. I’ll take the fifth on that one. Ask Fred.
See also: fifth, take