The Collaborative International Dictionary of English v.0.48:

Obelisk \Ob"e*lisk\, v. t. [imp. & p. p. Obelisked
   ([o^]b"[e^]*l[i^]skt); p. pr. & vb. n. Obelisking.]
   To mark or designate with an obelisk.
   [1913 Webster]