The Collaborative International Dictionary of English v.0.48:

Hack \Hack\, v. t. [imp. & p. p. Hacked (h[a^]kt); p. pr. &
   vb. n. Hacking.] [OE. hakken, AS. haccian; akin to D.
   hakken, G. hacken, Dan. hakke, Sw. hacka, and perh. to E.
   hew. Cf. Hew to cut, Haggle.]
   1. To cut irregulary, without skill or definite purpose; to
      notch; to mangle by repeated strokes of a cutting
      instrument; as, to hack a post.
      [1913 Webster]

            My sword hacked like a handsaw.       --Shak.
      [1913 Webster]

   2. Fig.: To mangle in speaking. --Shak.
      [1913 Webster]

   3. (Computers) To program (a computer) for pleasure or
      compulsively; especially, to try to defeat the security
      systems and gain unauthorized access to a computer.
      [PJC]

   4. To bear, physically or emotionally; as, he left the job
      because he couldn't hack the pressure. [Colloq.]
      [PJC]