expression
astonishing; amazing; surprising
A fixed prenominal expression (連体詞) meaning 'astonishing' or 'surprising'. It is used before nouns to express that something is remarkable or unexpected. It can carry a positive nuance like 'wonderful' depending on context.
彼は驚くべき速さで問題を解決した。
He solved the problem with astonishing speed.
この美術館には驚くべき作品がたくさんある。
This museum has many amazing works of art.