expression, adverb
even more; further; all the more
Emphasizes an increase in degree or intensity beyond what is already present. Often used in formal or written contexts.
彼の説明を聞いて、なお一層混乱した。
After hearing his explanation, I became even more confused.
努力を続ければ、なお一層の成果が期待できる。
If you keep making efforts, you can expect even greater results.
Compound of なお (still, yet) and 一層 (more, further), reinforcing the idea of an additional increase.