yes we need other resources.
dictionary.com is too weak for such software with professional vocabulary being read by people all around the world.

Thank you, Gij! Requestly works like a charm. However, I hope Adobe provides a more straightforward solution soon.

There seems to be consensus here that Acrobat DC needs to allow user to change the default lookup url.

However, I would like to use the default lookup tool in MacOS. It is easy to use and it doesn't require leaving the app to open a browser window (which is highly distracting while reading papers).

Unfortunately, it doesn't look like Adobe pays any attention to this these comments.

please let us choose a default as we can do in our browsers

I only use Firefox
I installed "Redirector" add-on and I edited it as in the attached image
Each time Acrobat wants to search on Dictionary - which is useless - it is redirected to Google
Et voila

Well what if the PDF file is open in Acrobat DC and not in chrome? In that case, extensions are no help. It would be preferable to have it by default searched on Google/ Bing/ other search engine.

Availability of Requestly extension and of what turns out to be a beta version of a Mac desktop application (which has far more appeal) looks interesting and a possible viable alternative to an Adobe sanctioned, and developed, native solution, save for two things.

I don't use the Google Chrome browser for Mac (nor its various descendants built on the same extension framework).

And the beta of the desktop application (which has more appeal, because, if I understand properly, it maybe allows what I suggested in the first place, and that is a way to choose the default dictionary lookup directly in Acrobat) is a non-starter as it clearly does not have validation from Apple as being safe on the Mac OS desktop. When the Requestly developer bothers to apply for and receive Apple certification I'll be happy to try it, and most likely buy a license.

As of present, the problem is still not solved. And, of course, it's not curious at all that Adobe is completely silent on this subject (and many related suggestions from users for alterations to the user interface or the request that choices be permitted in functionality).

Chrome extension 'Requestly 'can help you with that.

Download Requestly from https://chrome.google.com/webstore/detail/requestly-redirect-url-mo/mdnleldcmiljblolnjhpnblkcekpdkpa?hl=en

Find more in this article- https://requestly.medium.com/change-the-default-dictionary-in-adobe-acrobat-reader-86090c7f016

Yes please dump dictionary.com

agreeed

Any news?

agreed and hoping for an update that incorporates this

AGREED!!!!!!!!

Here's a workaround. You can use chrome plugin "requestly" and set up rules for replacing the dictionary.com part with your desired website in the URL generated from acrobat.

I was looking for such thing. It shouldn't be that much difficult to add this option in the next versions.

Thanks in advance Adobe!!!

Totally agree with you! How this issue can be solved in the near future!

exactly !

totally agree