noun, noun which may take the genitive case particle 'no'
open all night; all-night business
Describes a business, store, or service that operates throughout the night. Often used in signs or descriptions of convenience stores, restaurants, etc.
このコンビニは終夜営業です。
This convenience store is open all night.
終夜営業の店を探している。
I'm looking for a shop that's open all night.
24時間営業 explicitly means 'open 24 hours', while 終夜営業 emphasizes being open through the night (may not be 24 hours).
Compound of 終夜 (all night) + 営業 (business, operation).