オン

おん
noun
on (switched-on state)
1. on; switched-on state; activated
The 'on' state of a switch, device, or setting, as opposed to オフ ('off'). From English 'on'. Frequently used as オンにする ('to turn on') and in the pair オン/オフ.
スイッチをオンにする。
Turn the switch on.
通知(つうち)をオンにしておいた。
I left notifications turned on.
エアコンがオンのままだったので、電気代(でんきだい)(たか)くなった。
The air conditioner was left on, so the electricity bill went up.

Loanword from English 'on', referring to the activated state of a switch, device, or setting. Its opposite is オフ (off).

COMMON COLLOCATIONS:

  • オンにする: to turn on; to switch on
  • オン/オフ: on/off
  • オンの状態(じょうたい): the on state

USAGE:
Unlike the English preposition 'on', Japanese オン is used only for the switched-on/activated sense. The work-life sense also appears in オンとオフ ('on-duty and off-duty').

SIMILAR WORDS:

  • オフ: off — the opposite state
  • ()れる / ()る: to turn on / off — native verbs for operating a switch (電源(でんげん)()れる)