It would be cool for non english natives if Accordance would add some dict's.
BW has also some Translation lexicons. Maybe because they know, they have customers all over the world=Just a wild guess but maybe true.
In between there is some tools to download which works with the Mac own Lexicon. I have created a shortcut for this Bildschirmfoto 2016-04-18 um 14.43.22.png 134.89KB 0 downloads. That works, but the 3Finger tip Bildschirmfoto 2016-04-18 um 14.45.43.png 210.47KB 0 downloads from the Mac doesn't work in 11.1.6 hopefully in 11.2