noun, noun which may take the genitive case particle 'no'
the greatest of the day; the foremost in the present age
Used to describe someone or something considered the best in their field during the current era. Often appears in formal or literary contexts, such as historical descriptions or critical appraisals.
彼は当代第一の画家と称されている。
He is acclaimed as the greatest painter of the present age.
この作品は当代第一の傑作と言えるだろう。
This work can be called the foremost masterpiece of our time.
Compound of 当代 (present age) and 第一 (first, number one). The exact historical derivation is uncertain, but the combination follows standard Sino-Japanese word formation patterns.