The clue is another RT obtuse one, but lets try to explain at least some of it.The clue reads "Passed a boy above plain" the answer is I think OVERLADEN. Having said that I cant find a word in the clue that actually defines overladen.
En Well take your pick from the 20 or so definitions of the word En that appear in Wikipedia. Bearing in my the previous answers the compler(s) seem to like references to typography, so perhaps its something to do with that. No doubt others will be able to contribute more, or correct me if I am wrong.