What does 盛大 mean?
盛大 is a Japanese noun meaning “grand, prosperous, magnificent” in English. It can also be translated as “forceful” depending on context. It is written as 盛大 in kanji, せいだい in hiragana, and seidai in romaji. This word is part of JLPT N1 vocabulary.
Example sentence
盛大な溜息をつきながら、テーブルの上にどさどさとパンを置き、椅子にどっかりと腰掛ける。
Heaving a great sigh I plunk my bread on the table and flump onto the chair.