Used as a participial adjective derived from the verb “astound”.
The past participle "astounded" is often used adjectivally (e.g., "She looked astounded").
stupéfaitExprime l'état de grande surprise ou de choc. He was astounded by the unexpected news.
Il est resté stupéfait devant la nouvelle inattendue.
sidéréPlus intense ; registre soutenu.