► 形容動詞盛大 [せいだい]
meaning: extravagant rank: 2☆
会社の
創業百
周年パーティーが盛大に
開かれた ⇨ A 100th anniversary party of the company was held extravagantly
(☛ Usually about events)More examples:- 念願成就の暁には盛大な祝宴を挙げるつもりです ⇨ I will have a big party when all my wishes comes true