An error occurred while saving the commentJoka commented
This is essential and could be an USP on the windows os. I don't know a pdf app reader with this feature on the windows os.
Meanwile I use http://dynamictranslator.com/ as a workaround in addtion to xodo.
It copies and translate the word directly out of the clipboard without using paste or a shortcut. Just select the word in xodo, push the copy button and swipe to the explorer window. The only unconvinced thing is that the result is displayed in the explorer window because of the missing overlay feature.