1.
for emergency use; emergency (used as a modifier)
Designating equipment, supplies, or facilities meant to be used in an emergency rather than in normal operation. Usually attaches to another noun with の or as a prefix-like element.
非常用の食料を備える。
I keep emergency food supplies on hand.
非常用階段は建物の裏側にある。
The emergency stairs are on the back side of the building.
停電に備えて、非常用の電源を用意しておく必要がある。
We need to prepare an emergency power supply in case of a blackout.
Compound of 非常 (emergency) + 用 (for the use of). The 〜用 suffix is highly productive: 業務用 (commercial-use), 家庭用 (household-use), 子供用 (for children).
COMMON COLLOCATIONS:
- 非常用の食料: emergency food supplies
- 非常用階段: emergency stairs
- 非常用電源: emergency power supply
- 非常用持ち出し袋: emergency go-bag
- 非常用口: emergency exit
GRAMMAR:
Normally modifies another noun directly (非常用電源) or with の (非常用の水). Does not function as a standalone predicate.