electric rice warmer
A kitchen appliance that keeps cooked rice warm, often part of a rice cooker or a standalone unit.
炊飯器の電子ジャー機能でご飯を保温する。
I keep the rice warm using the electric warmer function of the rice cooker.
電子ジャーに入れておけば、夕方までご飯が温かい。
If you put it in the electric warmer, the rice stays warm until evening.
Compound of 電子 (electronic) and ジャー (from English 'jar'), referring to an electric container for keeping rice warm.