Translation guide
A mechanical device with rotating blades that pushes against air or water to move a vehicle.
プロペラ
propeller
The rotating bladed device used for propulsion or moving air.
The most common and general term for a propeller, used for aircraft, boats, and sometimes fans. A loanword from English.
飛行機のプロペラが回り始めた。
The airplane's propeller started spinning.
この船はプロペラが二つ付いている。
This boat has two propellers.
A more technical term meaning 'propulsion device'. Used in engineering or formal contexts.
この潜水艦は新型の推進器を搭載している。
This submarine is equipped with a new type of propeller.
Specifically refers to a screw propeller, often used for ships. Can also mean 'screw' in general.
船のスクリューが絡まって動けなくなった。
The ship's propeller got tangled and couldn't move.
Referring to the propeller as part of an aircraft or boat.
Natural way to say 'airplane propeller'.
飛行機のプロペラがうるさかった。
The airplane's propeller was loud.
Natural way to say 'boat propeller'.
船のプロペラに海藻が絡まった。
Seaweed got tangled in the boat's propeller.
プロペラ is understood by all Japanese speakers and is the safest choice for any context, from casual conversation to technical descriptions. Use 推進器 only in very formal or engineering documents.