besides; furthermore; on top of that
Adds an additional point or reason, often strengthening the preceding statement. Used in both spoken and written Japanese.
This restaurant is cheap, and on top of that, delicious.
He is smart. Furthermore, he is a hard worker.
This shop is cheap. On top of that, the quality is good.
and yet; nevertheless; even so
Introduces a contrasting point that does not negate the previous statement. Often used to acknowledge a fact while adding a counterpoint.
He is young. And yet, he has a lot of experience.
The price is high. Nevertheless, it is popular.
He's busy, and yet he still keeps exercising every day.
その上 is a slightly casual, everyday way to say 'on top of that', whereas なおかつ carries a more formal or emphatic tone.
尚更 (なおさら) means 'all the more' and is often confused with なおかつ because of their similar sound and shared 尚 kanji, but 尚更 intensifies a degree while なおかつ adds a separate point.
Kana spelling is standard; the word is usually written in kana.
Kanji form is rare and mostly seen in formal or literary writing.
Search-only kanji form; not a standard spelling.
Compound of なお (still, furthermore) and かつ (moreover, besides). The kanji spellings are ateji and rarely used.