From none + the (Etymology 2), where both words are adverbs. Literally meaning, "not at all".
none the (comparative more none the, superlative most none the)
- Having no further or greater of a stated quality than before, used in phrases with comparative adjectives such as worse, better, wiser, etc., and often followed by for.
- Mahatma Gandhi, The Story of My Experiments with Truth, translated by Mahadev Desai, Part I, chapter v:
- I may mention, however, that I was none the worse for abstaining from exercise. That was because […] , I had formed a habit of taking walks, which has still remained with me. These walks gave me a fairly hardy constitution.