Pressing Ctrl-Backspace deletes a word in a <textarea> in Firefox. It works the same way in VisualEditor when the wiki's language is English, but if it's Hebrew, it only deletes one character.
A GWT testing scenario for this would be something like this:
Given $wgLanguageCode is 'he'
And I am editing an article And I wrote 'אחת שתיים שלוש'
When I press Ctrl-Backspace
Then the remaining text is 'אחת שתיים '