The words "weapon" and "arm" are sometimes confused, but they have distinct meanings. "Weapon" refers to any object used to inflict harm or injury, whether it's a gun, a knife, a sword, or even a rock. "Arm," on the other hand, refers to a limb of the body, specifically the part extending from the shoulder to the hand. It can also refer to a branch of military service, like the army or the navy, and in some cases a branch of government, such as the "executive arm" of government.

Here are some example sentences illustrating the difference:

• He used a knife as a weapon to defend himself. (Meaning: He used a knife to fight back.)

• Translation: He employed a knife as a means of self-defense.

• She raised her arm to shield her face. (Meaning: She lifted her arm to protect her face.)

• Translation: She lifted her upper limb to defend her facial area.

• The soldier carried a weapon into battle. (Meaning: The soldier took a tool of war to fight.)

• Translation: The soldier brought a tool of combat into the battlefield.

• The police were able to disarm the suspect's weapon. (Meaning: Police removed the weapon from the suspect.)

• Translation: Law enforcement successfully took away the suspect's instrument of harm.

• The criminal justice system is a powerful arm of government. (Meaning: The justice system is a significant and effective part of the government.)

• Translation: The legal system of prosecuting and punishing criminals is a strong and influential branch of the governing body.

• He has a strong right arm. (Meaning: His right arm is physically powerful.)

• Translation: His right upper limb exhibits significant physical strength.

Notice that "weapon" always refers to an object used to harm, while "arm" can refer to a body part or a division of a larger entity. The context is important in determining the meaning.

Happy learning!