What is Objection?

Legal Definition
In the law of the United States of America, an objection is a formal protest raised in court during a trial to disallow a witness's testimony or other evidence which would be in violation of the rules of evidence or other procedural law. An objection is typically raised after the opposing party asks a question of the witness, but before the witness can answer, or when the opposing party is about to enter something into evidence. The judge then makes a ruling on whether the objection is "sustained" (the judge agrees with the objection and disallows the question, testimony, or evidence) or "overruled" (the judge disagrees with the objection and allows the question, testimony, or evidence). An attorney may choose to "rephrase" a question that has been objected to, so long as the judge permits it. Lawyers should make an objection before there is an answer to the question.
-- Wikipedia
Legal Definition
A formal protest raised during a trial, deposition or other procedure indicating that the objecting attorney wishes the judge to disallow either the testimony of a given witness or other evidence that would violate the rules of evidence or other procedural law. At trial, these are typically raised after the opposing party poses a question of the witness, but before the witness can answer, or when the opposing party seeks to enter an exhibit into evidence.

Once an attorney makes an objection, the judge then makes a ruling. If a judge sustains the objection, it means that the judge agrees with the objection and disallows the question, testimony or evidence. If the judge overrules the objection, it means that the judge disagrees with the objection and allows the question, testimony or evidence. The judge may also permit the attorney to rephrase the question to correct whatever was objectionable.

Objections may also occur in response to the conduct of a judge.

Some common objections include:

1. Irrelevant. That the testimony pursuant to a question asked or the particular item of evidence is not relevant to the case.

2. The witness is incompetent.

3. Violation of the best evidence rule.

4. Violation of the hearsay rule.

5. Speculative. That the question calls for the witness to speculate about something.

6. Leading. When the question posed by the attorney seeks to lead the witness to make an assertion.

7. Violation of the parol evidence rule.

8. Repetitive. (also Asked and answered). The question has already been asked and answered.
Legal Definition
The act of a party who objects to some matter or proceeding in the course of a trial, (see Object, v. .-) or an argument or reason urged by him in support of his contention that the matter or proceeding objected to is Improper or illegal.
-- Black's Law Dictionary
Legal Definition
Sometimes synonymous with “exception,” but an objection is made that a ruling of the court may be had and when the court acts, the error is preserved by an exception to the ruling. See 232 Mo. 444, Ann. Cas. 1912B, 1221, 134 S. W. 641.
-- Ballentine's Law Dictionary