A picnic; an outdoor leisure activity involving bringing food to eat and relaxing in a park or other outdoor spot.
週末に家族とピクニックに行ってお弁当を食べた。
We went on a picnic with the family on the weekend and ate boxed lunches.
桜の季節には公園でピクニックをする人が多い。
Many people have picnics in the park during cherry blossom season.
ピクニック用のレジャーシートを忘れずに持ってきてください。
Don't forget to bring a picnic sheet.
A dated term meaning an outing or hike; historically used more broadly for excursions.
祖父が若い頃は、ピクニックに出かけて山を歩いたという。
My grandfather said that when he was young he would go on outings and walk in the mountains.
昔の文献ではピクニックが遠足の意味で使われる例が見られる。
In older literature, you can find examples where 'picnic' is used to mean an excursion.