A more thorough explanation:

A corroborating witness is someone who provides testimony that supports or confirms the testimony given by another person in a current case. This type of witness is particularly important in certain types of cases, such as divorce cases in some states.

In Virginia, a corroborating witness is required in divorce cases to prove to the judge that the grounds for the divorce are satisfied. For example, if one spouse claims that the other committed adultery, a corroborating witness might be someone who saw the alleged affair take place or who has other evidence to support the claim.

In Maryland and West Virginia, corroboration in the context of divorce generally requires a third-party witness to support the claim for a divorce. For example, if one spouse claims that the other was abusive, a corroborating witness might be someone who saw or heard the abuse take place, or who has other evidence to support the claim.

These examples illustrate how a corroborating witness can provide important evidence to support a claim in a legal case. Without a corroborating witness, it may be more difficult to prove that the claims being made are true.