Sentence:  Yet there was no time to be lost if I was ever to get out alive, and so I <WSD>groped</WSD> with my hands against the side of the grave until I made out the bottom edge of the slab, and then fell to grubbing beneath it with my fingers. But the earth, which the day before had looked light and loamy to the eye, was stiff and hard enough when one came to tackle it with naked hands, and in an hour's time I had done little more than further weary myself and bruise my fingers. 
Meaning of the word marked with <WSD> tags:  To search or attempt to find something in the dark, or, as a blind person, by feeling; to move about hesitatingly, as in darkness or obscurity; to feel one's way, as with the hands, when one can not see.