bat- +

1. To lessen or to make something decrease gradually.
2. To suppress or to end a nuisance, act, or writ, or to be suppressed or ended.
3. To lower the amount or rate of something; such as, a tax.
4. Etymology: from Old French abattre, "to beat down"; from Latin ad-, "to" + battuere, "to beat".

1. An interruption in the intensity or the amount of something.
2. Diminution in amount, degree, or intensity; moderation.
3. The amount lowered; a reduction.
4. A diminution, a decrease or an easing.

In medicine there may be an abatement of pain or any other symptom or sign of a physical ailment. In the environment there may be an abatement in the degree of pollution.

1. To make sour or bitter.
2. To irritate, vex, or annoy.

1. To hit with or as if with a club or bat: "When he batted the ball that day, he set a record."
2. Informal, to produce hurriedly: "She batted out a speech in a short time."
3. To discuss or consider at some length: "They batted the idea around."
4. To wink or flutter: "She batted her eyelashes."

1. Beaten; bruised, broken, impaired by beating or wearing.
2. Damaged; especially, by hard usage: "He wore hi battered old hat."
3. Beaten repeatedly with heavy blows: "He was battered by street thugs."
4. Damaged by blows or hard usage; such as, a battered car.

1. The act of subjecting to strong attack.
2. A situation in which someone is repeatedly hit.
3. A severe criticism, defeat, or setback: "He took a battering from his critics."

1. A blacksmith's hammer, suspended, and worked horizontally.
2. An engine used in ancient times to beat down the walls of besieged places (forts, castles, etc.).

A battering ram is a siege engine originating in ancient times to break open fortification walls, or entrance ways.

1. A large-scale fight between armed forces involving combat between armies, warships, or aircraft.
2. A drawn-out conflict between adversaries, or against powerful forces: "There is still a prolonged battle against malaria."
3. An intense competition; such as, "a battle of wits" or "a political battle for President".
4. Etymology: from Old French bataille, from Late Latin battualia, "an exercise of soldiers and gladiators in fighting and fencing"; from Latin battuere, "to beat".

1. To attempt to destroy or to control something considered to be harmful; such as, measures to combat pollution.
2. To resist or to oppose (to beat or to defeat) someone or something actively.

1. Anyone who attempts to destroy or to control something considered to be harmful; such as, measures to combat pollution.
2. Someone who resists or opposes (beats or defeats) someone or something actively.

An indication that something may, or may not be, true or real: "Whether the politician's report is accurate is debatable."

1. A discussion in which reasons are advanced for and against some proposition or proposal. 2. To talk about something at length and in detail; especially, as part of a formal exchange of opinions.
3. To ponder, or to think, about something carefully: "The accuracy of the doctor's opinion was open to debate by his colleagues." 4. Etymology: from French debattre; originally, "to fight"; from de-, "down, completely" + batre "to beat".

1. Someone who debates, or participates in a debate: "She is the best debater on our university team."
2. A disputant or someone who is involved in a formal discussion in a public meeting or legislature, in which opposing arguments are presented.

1. That which can be returned as part of an original payment for some service or merchandise.
2. The possibility of being partially refunded.

1. Money that is paid back; for example, because someone has overpaid a tax or is entitled to a refund.
2. A discount or deduction on a sales price; to give a discount or deduction.
3. A return of part of an original payment for some service or merchandise; a partial refund.
4. Also a reference to a rabbet or a cut, or a groove, along or near the edge of a piece of wood that allows another piece to fit into it to form a joint.
5. Etymology: "to deduct, subtract" comes from Old French rabattre, "to beat down, to drive back"; also "deduct", from re-, "repeatedly" + abattre, "to beat down".

The meaning "to pay back (a sum) as a rebate" is believed to come from 1957.