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to celebrate; to congratulate; to observe (a festival)
to present (a gift) in celebration; to drink in celebration
to wish for (a happy future, good fortune, etc.); to pray for
新年を家族で集まって斎うのが恒例だ。
It's customary for the family to gather and celebrate the New Year.
友人の誕生日をみんなで斎って楽しんだ。
We all celebrated our friend's birthday and had fun.
合格を友人と斎った。
I celebrated passing with friends.