On Thu, Oct 01, 2020 at 05:39:29PM +0300, Jean Louis wrote:

[...]

> As long as dict database of Wiktionary exists, as I think, by the
> license, it should exist, so I have asked the webmaster to tell me
> about that.

I think all those questions are answered in their web pages. The
license(s) are here [1]. The download question is in the FAQ [2]:

"Q: Is it possible to download Wiktionary?

 A: Yes. https://dumps.wikimedia.org/enwiktionary/ should have
    the latest copy of the main namespace. The cleanest navigation
    page is https://dumps.wikimedia.org/. Just download a
    *-articles.xml.bz2 file and some software to read it (for
    *nix, for Windows).

(The "for *nix..." are actually links to software).

Cheers

[1] https://en.wiktionary.org/wiki/Wiktionary:About
[2] https://en.wiktionary.org/wiki/Help:FAQ#Downloading_Wiktionary

 - t