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still more; even more; all the more
still less; even less
彼が行かないならなおさら私も行かない。
If he's not going, I'm all the more not going.
経験があるならなおさら注意すべきだ。
If you have experience, you should be even more careful.
そう言われるとなおさらやる気が出る。
Being told that makes me all the more motivated.