I'm launching Elseword tomorrow, an AI dictionary built around what you mean, not a fixed list of entries.

The reason I built it: the words I actually needed were never entries. "A polite way to disagree with my manager." "A word for caring about the tiniest details." A dictionary can't answer that; it only answers if you already know the word.

The other reason is that I don't think in one language. I'd meet a word in Chinese, wonder how it lands in Japanese, then want the English sense too, and I'd be three apps deep with a different dictionary for each, losing the thread every time I switched.