リアシートリアシートMeanings1nounrear seat; back seatRefers to the back seat of a vehicle, especially a car. A straightforward loanword from English.子こ供どもはリアシートに座すわらせてください。Please have children sit in the rear seat.この車くるまのリアシートは広ひろい。The rear seat of this car is spacious.