The clue was "What a lover's heart is opposed to" and the answer was "versus". I don't get it. I see that "opposed to" equals versus but the alternative route to the answer I can't see. You could say that "vers" is the heart of "lovers" as it is part of the word (though it's not really the heart) but in that case, whence comes the "us"? I wondered if it is perhaps a poetic reference to some famous poem or quote that I just don't know.