also: イヴ
eve; night before
Primarily refers to Christmas Eve (クリスマスイブ), but can be used for the eve of other events. A loanword from English 'eve'.
クリスマスイブに家族で集まる。
We gather with family on Christmas Eve.
大晦日
I spent a quiet Christmas Eve with my girlfriend.
New Year's Eve can be called the eve of the new year.
結婚式のイブに、両親から手紙をもらった。
On the eve of the wedding, I received a letter from my parents.
Most common katakana spelling; matches the priority reading.
Alternate katakana spelling; less common but still seen.
Loanword from English 'eve', entering Japanese primarily through the phrase クリスマスイブ (Christmas Eve).