WordNet (r) 3.0 (2006):

PM
    n 1: an examination and dissection of a dead body to determine
         cause of death or the changes produced by disease [syn:
         autopsy, necropsy, postmortem, post-mortem, PM,
         postmortem examination, post-mortem examination]
    2: a soft silvery metallic element of the rare earth group
       having no stable isotope; was discovered in radioactive form
       as a fission product of uranium [syn: promethium, Pm,
       atomic number 61]
    3: the person who holds the position of head of the government
       in the United Kingdom [syn: Prime Minister, PM,
       premier]
    4: modulation of the phase of the carrier wave [syn: phase
       modulation, PM]

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

PM

   1. preventive maintenance.

   2. Presentation Manager

   3. ["PM, A System for Polynomial Manipulations", G.E. Collins,
   CACM 9(8):578-589 (Aug 1966)].

   [Jargon File]


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

pm

    The country code for St. Pierre and Miquelon.

   (1999-01-27)


The Jargon File (version 4.4.7, 29 Dec 2003):

PM
 /P·M/

    1. v. (from preventive maintenance) To bring down a machine for inspection
    or test purposes. See provocative maintenance; see also scratch monkey.

    2. n. Abbrev. for ‘Presentation Manager’, an elephantine OS/2 graphical
    user interface.