Sentence:  But in that gale, the port, the land, is that ship's direst jeopardy; she must fly all hospitality; one touch of land, though it but <WSD>graze</WSD> the keel, would make her shudder through and through. 
Meaning of the word marked with <WSD> tags:  To rub or touch lightly the surface of (a thing) in passing.