You know what really grinds my gears?

Yeah, people use this word so often, and yet it's almost always used wrong. I don't know why, but this annoys me so much.

For the record, the legal definition of the word hearsay:
"An out-of-court statement offered to prove the truth of the matter asserted."

So any time a person says something out of court (oral or written), as long as the statement they said was to assert the truth, it's hearsay.

Not every statement a person makes out of court is hearsay.
For example:
- A command is not hearsay,
- questions are not hearsay,
(Remember that questions seek truth, they don't assert it)

It's not considered hearsay without a declarant. 
For example:
-A police dog that alerted the cops to the narcotics is not considered a declarant. 

Just because something is hearsay, does not mean it's inadmissible.

Rule 803. Exceptions to the Rule Against Hearsay

The following examples are not excluded by the rule against hearsay, regardless of whether the declarant is available as a witness:

- Present Sense Impression. 

A statement describing or explaining an event or condition, made while or immediately after the declarant perceived it.

- Excited Utterance. 

A statement relating to a startling event or condition, made while the declarant was under the stress of excitement that it caused.

- Then Existing Mental, Emotional, or Physical Condition.

A statement of the declarant’s then-existing state of mind (such as motive, intent, or plan) or emotional, sensory, or physical condition (such as mental feeling, pain, or bodily health), but not including a statement of memory or belief to prove the fact remembered or believed unless it relates to the validity or terms of the declarant’s will.

- Statement Made for Medical Diagnosis or Treatment. 

A statement that:

• is made for — and is reasonably pertinent to — medical diagnosis or treatment; and
• describes medical history; past or present symptoms or sensations; their inception; or their general cause.

- Recorded Recollection. 

A record that:

• is on a matter the witness once knew about but now cannot recall well enough to testify fully and accurately;
• was made or adopted by the witness when the matter was fresh in the witness’s memory; and
• accurately reflects the witness’s knowledge.

If admitted, the record may be read into evidence but may be received as an exhibit only if offered by an adverse party.

- Records of a Regularly Conducted Activity. 

A record of an act, event, condition, opinion, or diagnosis if:

• the record was made at or near the time by — or from information transmitted by — someone with knowledge;
• the record was kept in the course of a regularly conducted activity of a business, organization, occupation, or calling, whether or not for profit;
• making the record was a regular practice of that activity;
• all these conditions are shown by the testimony of the custodian or another qualified witness, or by a certification that complies with Rule 902(11) or (12) or with a statute permitting certification; and
• neither the opponent does not show that the source of information nor or the method or circumstances of preparation indicate a lack of trustworthiness.

- Absence of a Record of a Regularly Conducted Activity. 

Evidence that a matter is not included in a record described in paragraph (6) if:

• the evidence is admitted to prove that the matter did not occur or exist;
• a record was regularly kept for a matter of that kind; and
• neither the opponent does not show that the possible source of the information nor or other circumstances indicate a lack of trustworthiness.

- Public Records. 

A record or statement of a public office if:

• it sets out:i.) the office’s activities;ii.) a matter observed while under a legal duty to report, but not including, in a criminal case, a matter observed by law-enforcement personnel; oriii.) in a civil case or against the government in a criminal case, factual findings from a legally authorized investigation; and
• neither the opponent does not show that the source of information nor or other circumstances indicate a lack of trustworthiness.

- Public Records of Vital Statistics. 

A record of a birth, death, or marriage, if reported to a public office in accordance with a legal duty.

And there is more, but I won't get into all of them now. If you would like to see them all for yourself click here for Cornell University's page on Rule 803. Exceptions to the Rule Against Hearsay.

Rule 804. Hearsay Exceptions; Declarant Unavailable

- The Exceptions. The following are not excluded by the rule against hearsay if the declarant is unavailable as a witness:

(1) Former Testimony. Testimony that:

(A) was given as a witness at a trial, hearing, or lawful deposition, whether given during the current proceeding or a different one; and

(B) is now offered against a party who had — or, in a civil case, whose predecessor in interest had — an opportunity and similar motive to develop it by direct, cross-, or redirect examination.

(2) Statement Under the Belief of Imminent Death.

In a prosecution for homicide or in a civil case, a statement that the declarant, while believing the declarant’s death to be imminent, made about its cause or circumstances.

(3) Statement Against Interest. 

A statement that:

(A) a reasonable person in the declarant’s position would have made only if the person believed it to be true because, when made, it was so contrary to the declarant’s proprietary or pecuniary interest or had so great a tendency to invalidate the declarant’s claim against someone else or to expose the declarant to civil or criminal liability; and

(B) is supported by corroborating circumstances that clearly indicate its trustworthiness, if it is offered in a criminal case as one that tends to expose the declarant to criminal liability.

(4) Statement of Personal or Family History. 

A statement about:

(A) the declarant’s own birth, adoption, legitimacy, ancestry, marriage, divorce, relationship by blood, adoption, or marriage, or similar facts of personal or family history, even though the declarant had no way of acquiring personal knowledge about that fact; or

(B) another person concerning any of these facts, as well as death, if the declarant was related to the person by blood, adoption, or marriage or was so intimately associated with the person’s family that the declarant’s information is likely to be accurate.

(5) [Other Exceptions .] [Transferred to Rule 807.]

(6) Statement Offered Against a Party That Wrongfully Caused the Declarant’s Unavailability. 

A statement offered against a party that wrongfully caused — or acquiesced in wrongfully causing — the declarant’s unavailability as a witness, and did so intending that result.

Here's a link to Cornell University's page on Rule 804.

So as you can see, there's a lot more to the word "hearsay" then most people think. I hope this has given a little more insight.