noun-modifying (irregular)
Prenominal adjective used to describe something as exactly the same as another. Common in technical or formal contexts.
二つのサンプルはアイデンティカルな結果を示した。
The two samples showed identical results.
アイデンティカル is a loanword used mainly as a prenominal adjective in technical contexts, while 同一 is a native Sino-Japanese word used more broadly as a noun or adjective.
Borrowed from English 'identical'.