The Free On-line Dictionary of Computing (30 December 2018):

LDB

   /l*'d*b/ [PDP-10 instruction] To extract from the middle.
   "LDB me a slice of cake, please."  This usage has been kept
   alive by Common LISP's function of the same name.  Considered
   silly.  See also DPB.

   [Jargon File]