WordNet (r) 3.0 (2006):

pdl
    n 1: a unit of force equal to the force that imparts an
         acceleration of 1 foot/sec/sec to a mass of 1 pound; equal
         to 0.1382 newtons [syn: poundal, pdl]

The Free On-line Dictionary of Computing (19 January 2023):

PDL

   1. Page Description Language.

   2. Program Design Language.

   3. Push Down List.

   4. Dave Lebling, one of the co-authors of Zork.  His
   network address on the ITS machines was at one time
   .

   5. Propositional Dynamic Logic.

   [Jargon File]