operation

手術

医師が体を切り開き、悪い部分を治したり取り除いたりする治療。

やさしい英語で： Medical treatment in which a doctor cuts into the body to repair or remove something.

• My father needs an operation.
• The operation on her knee went well.
• How long will you stay in hospital after the operation?

使い方： an operation on something (He had an operation on his knee.); an operation to do something (She needs an operation to remove the lump.)

類義語： surgery, surgical procedure

よく使う表現： have an operation, heart operation, operation on something, emergency operation

作戦、活動

集団が目的のために行う計画的な活動。特に軍や警察、救助隊の活動。

やさしい英語で： A planned activity by a group working towards a goal, especially soldiers, police, or rescue workers.

• The rescue operation saved six people.
• Soldiers carried out the operation at night.
• Police launched an operation to find the stolen cars.

類義語： mission, campaign

よく使う表現： military operation, rescue operation, police operation, launch an operation

事業、業務

企業やその一部、またはそこで行われる仕事。

やさしい英語で： A business or part of a business, including the work it does.

• Their bakery is a small operation.
• The company expanded its overseas operations.
• She manages the firm's entire European operation.

類義語： business, enterprise

よく使う表現： business operation, overseas operation, expand an operation, small operation

作動、動作

機械が動く仕組み、または動いている状態。

やさしい英語で： The way a machine works, or the state of working.

• The lift is back in operation.
• This button controls the operation of the fan.
• Read the instructions for safe operation before using the machine.

使い方： in operation (Keep your hands away while the machine is in operation.); the operation of something (The guide explains the operation of the pump.)

類義語： functioning, working

よく使う表現： in operation, safe operation, automatic operation, operation of something

演算、計算

足し算や割り算など、数学の記号で表される数の計算。

やさしい英語で： An action with numbers, such as adding or dividing, shown by a mathematical sign.

• Addition is a basic mathematical operation.
• Which operation does this symbol represent?
• Perform the operations inside the brackets first.

類義語： calculation

よく使う表現： mathematical operation, basic operation, operation symbol, arithmetic operation

運用、実施

活動や手順、仕組みを実際にどう進め、動かすかということ。

やさしい英語で： The way an activity, process, or system is carried out.

• Their method of operation was simple.
• The review examined the operation of the complaints system.
• Clear rules are essential for the smooth operation of the scheme.

使い方： the operation of something (We reviewed the operation of the new rules.)

類義語： working, functioning, procedure

よく使う表現： method of operation, mode of operation, normal operation, operation of something