expression
not only ... but (also); as well as ...
A conjunction-like expression used to add another element, often paired with も or まで. Similar to だけでなく but slightly more formal or written.
彼は日本語ばかりでなく、中国語も話せる。
He can speak not only Japanese but also Chinese.
この店は値段が安いばかりでなく、品質も良い。
This shop is not only cheap but also good quality.