Collins COBUILD Advanced Learner’s Dictionary

arith|me|tic The noun is pronounced /ər I θm I t I k/. The adjective is pronounced /æ r I θme t I k/. 1 N‑UNCOUNT Arithmetic is the part of mathematics that is concerned with the addition, subtraction, multiplication, and division of numbers. □  …an arithmetic test.

2 N‑UNCOUNT [oft poss N ] You can use arithmetic to refer to the process of doing a particular sum or calculation. □  4,000 women put in ten rupees each, which if my arithmetic is right adds up to 40,000 rupees.

3 N‑UNCOUNT If you refer to the arithmetic of a situation, you are concerned with those aspects of it that can be expressed in numbers, and how they affect the situation. □  The budgetary arithmetic suggests that government borrowing is set to surge.

4 ADJ [ADJ n] Arithmetic means relating to or consisting of calculations involving numbers. □  …simple arithmetic operations such as adding or multiplying numbers.

arith|meti|cal /æ r I θme t I k ^ə l/ ADJ [usu ADJ n] Arithmetical calculations, processes, or skills involve the addition, subtraction, multiplication, or division of numbers.

ark /ɑː ^r k/ N‑SING In the Bible, the ark was a large boat which Noah built in order to save his family and two of every kind of animal from the Flood.

arm

➊ PART OF YOUR BODY OR OF SOMETHING ELSE

➋ WEAPONS

➊ arm ◆◆◆ /ɑː ^r m/ (arms )

1 N‑COUNT [oft poss N ] Your arms are the two long parts of your body that are attached to your shoulders and that have your hands at the end. □  She stretched her arms out. □  He had a large parcel under his left arm.

2 N‑COUNT The arm of a piece of clothing is the part of it that covers your arm.

3 N‑COUNT The arm of a chair is the part on which you rest your arm when you are sitting down.

4 N‑COUNT An arm of an object is a long thin part of it that sticks out from the main part. □ [+ of ] …the lever arm of the machine. □ [+ of ] …the arms of the doctor's spectacles.

5 N‑COUNT An arm of land or water is a long thin area of it that is joined to a broader area. □ [+ of ] At the end of the other arm of Cardigan Bay is Bardsey Island.

6 N‑COUNT [usu sing] An arm of an organization is a section of it that operates in a particular country or that deals with a particular activity. □ [+ of ] Millicom Holdings is the British arm of an American company.

7 PHRASE If two people are walking arm in arm , they are walking together with their arms linked. □ [+ with ] He walked from the court arm in arm with his wife.

8 PHRASE If you say that something costs an arm and a leg , you mean that it is very expensive. [INFORMAL ] □  A week at a health farm can cost an arm and a leg.

9 PHRASE If you hold something at arm's length , you hold it away from your body with your arm straight. □  He struck a match, and held it at arm's length.

10 PHRASE If you keep someone at arm's length , you avoid becoming too friendly or involved with them. □  She had always kept his family at arm's length.

11 PHRASE If you welcome some action or change with open arms , you are very pleased about it. If you welcome a person with open arms , you are very pleased about their arrival. [APPROVAL ] □  They would no doubt welcome the action with open arms.

12 PHRASE If you twist someone's arm , you persuade them to do something. [INFORMAL ] □  She had twisted his arm to get him to invite her.

➋ arm ◆◆◆ /ɑː ^r m/ (arms , arming , armed )

1 N‑PLURAL [oft N n] Arms are weapons, especially bombs and guns. [FORMAL ] □  The group had extensive supplies of arms. □  …arms control.

2 VERB If you arm someone with a weapon, you provide them with a weapon. □ [V n + with ] She'd been so terrified that she had armed herself with a loaded rifle. □ [V n] Arming the police doesn't deter crime.