Hearsay

Evidence presented by a witness who did not see or hear the incident in question but heard about it from someone else. With some exceptions, hearsay generally is not admissible as evidence at trial.

Additional Sources

Answers.com

Evidence based on the reports of others rather than the personal knowledge of a witness and therefore generally not admissible as testimony.

Duhaime Legal Dictionary

Any evidence that is offered by a witness of which they do not have direct knowledge but, rather, their testimony is based on what others have said to them.

The evidence may be admissible to show that another person's statement was made, but not of the truth of what was contained therein.

Encyclopedia Britannica

In Anglo-American law, testimony that consists of what the witness has heard others say. United States and English courts may refuse to admit testimony that depends for its value upon the truthfulness and accuracy of one who is neither under oath nor available for cross-examination. The rule is subject, however, to many exceptions. In continental European law, where there is no jury to be protected from misleading testimony, judges may consider any evidence that they consider pertinent to reaching a decision.

FindLaw

A statement made out of court and not under oath which is offered as proof that what is stated is true.

Law.com Dictionary

1) second-hand evidence in which the witness is not telling what he/she knows personally, but what others have said to him/her. 2) a common objection made by the opposing lawyer to testimony when it appears the witness has violated the hearsay rule. 3) scuttlebutt or gossip.

Lect Law Library

Secondhand information that a witness only heard about from someone else and did not see or hear himself. Hearsay is not admitted in court because it's not trustworthy, as well as because of various constitutional principles such as the right to confront one's accusers, however, there are so many exceptions that often times hearsay is admitted more than excluded.

The Free (Legal) Dictionary

A statement made out of court that is offered in court as evidence to prove the truth of the matter asserted.

It is the job of the judge or jury in a court proceeding to determine whether evidence offered as proof is credible. Three evidentiary rules help the judge or jury make this determination: (1) Before being allowed to testify, a witness generally must swear or affirm that his or her testimony will be truthful. (2) The witness must be personally present at the trial or proceeding in order to allow the judge or jury to observe the testimony firsthand. (3) The witness is subject to cross-examination at the option of any party who did not call the witness to testify.

Wikipedia

Hearsay is information gathered by Person A from Person B concerning some event, condition, or thing of which Person A had no direct experience. When submitted as evidence, such statements are called hearsay evidence. As a legal term, "hearsay" can also have the narrower meaning of the use of such information as evidence to prove the truth of what is asserted. Such use of "hearsay evidence" in court is generally not allowed. This prohibition is called the hearsay rule.