Sentence:  Thus, sitting where I was, I lit my candle once more, and then clambered across that great coffin which, for two hours or more, had been a mid-wall of partition between me and danger. But to get out of the niche was harder than to get in; for now that I had a candle to light me, I saw that the coffin, though sound enough to outer view, was <WSD>wormed</WSD> through and through, and little better than a rotten shell. So it was that I had some ado to get over it, not daring either to kneel upon it or to bring much weight to bear with my hand, lest it should go through. 
Meaning of the word marked with <WSD> tags:  Affected with woodworm.