This is the 3508th most frequent Japanese word.
絶賛
"絶賛" means "high praise" or "great acclaim."
In this sentence, '絶賛' (zessan) is used as a noun in its verb form '絶賛される', which means 'to receive acclaim or high praise'.
その映画は絶賛されています。
That movie is receiving high praise.
Here, '絶賛' is part of the phrase '絶賛の的' (zessan no mato), implying something that is being highly praised by many.
彼の新しい料理が絶賛の的になっている。
His new dish is the subject of acclaim.
In this case, '絶賛される', the verb form, highlights the act of receiving high praise for work or achievements.