This removes the definitions only for current lesson (but for all of its sentences!) - not a huge issue for me, because I usually use lessons as long as possible.
Presumably can be implemented as some sort of quick AdBlock filter or GreaseMonkey script.
In Chrome, in order to hide the definitions, just right-click on a definition, select “Inspect”, go up the Elements list until you find a “ul” tag with “class” containing “sent-vocab-list”, right-click on that tag and select “Delete element.”
