Hearsay, in a legal forum, is an out-of-court statement which is being offered in court for the truth of what was asserted. In most courts, hearsay evidence is inadmissible (the "hearsay evidence rule") unless an exception to the hearsay rule applies.

For example, to prove that Tom was in town, a witness testifies, "Susan told me that Tom was in town." Because the witness's evidence relies on an out-of-court statement that Susan made, if Susan is unavailable for cross-examination,