oath-helping

Testimony introduced for the purpose of bolstering the credibility of a witness and their testimony, rather than proving or disproving a fact in issue; it is often inadmissible.

The rule against oath-helping prohibits a party from presenting evidence solely for the purpose of bolstering a witness' credibility before that witness' credibility is attacked. This type of evidence is of the sort that would tend to prove the truthfulness of the witness, rather than the truth of the witness' statements.

Compurgation.