Source : Webster's Revised Unabridged Dictionary (1913)

Delve \Delve\v. t. [imp. & p. p. {Delved}; p. pr. & vb. n.
   {Delving}.] [AS. delfan to dig; akin to OS. bidelban to bury,
   D. delven to dig, MHG. telben, and possibly to E. dale. Cf.
   {Delf} a mine.]
   1. To dig; to open (the ground) as with a spade.

            Delve of convenient depth your thrashing floor.
                                                  --Dryden.

   2. To dig into; to penetrate; to trace out; to fathom.

            I can not delve him to the root.      --Shak.