PM stands for Perdana Menteri in Malayia and Prime Minister in some countries.
PM described by wikipedia http://en.wikipedia.org/wiki/PM as below:-
- Particulate matter, particulates — fine dust and soot — suspended in the air
- PM10, particulates, smaller than 10μm, that can cause health problems
- PM3 (chemistry), or Parameterized Model number 3 – a modelling method in computational chemistry
- Permanent magnet, an object which stays magnetised without external effort
- Perpetual motion, refers to movement that goes on forever
- Petameter, a length unit (1015 m) (Pm)
- Phase modulation, in electrical engineering
- PM tube, Photomultiplier tube.
- Picometre, a length unit (10-12 m) (pm)
- Plasma membrane, is a selectively permeable lipid bilayer found in all cells
- Powdery mildew, a fungal disease that affects a wide range of plants
- Powder metallurgy, a method of fabricating metals.
- Premolar tooth, dental nomenclature
- Promethium, chemical element number 61 (Pm)
- Post mortem, a medical examination carried out after death
- Principia Mathematica, a three-volume work on the foundations of mathematics
- Polarization-maintaining optical fiber
 Computing and Internet
- Pac-Man, character, video game, and TV series
- Paper Mario, game for Nintendo 64
- Particle Mesh, an algorithm for calculating the potential of a system (used in computational physics).
- Perl module, a discrete component of software for the Perl programming language.
- Personal message or private message, a type of e-mail within community sites or chat between two people.
- P.M. Place Stores, a former US chain of discount stores
- Altria Group, previously named “Phillip Morris”
- Power Machines or Silmash, a Russian industrial company
- Project manager or project management, the discipline of organizing and managing resources
- Pobjoy Mint, a European mint, via its mint mark PM
- Precious metal, a rare metallic chemical element of high economic value
- IATA airline designator for Tropic Air
- 3pm, a former New Zealand children’s programme
- PM, an ABC Radio national news magazine programme
- PM, BBC Radio 4‘s long-running early evening news and current affairs programme.
- PM, a politically leftist U.S. newspaper in the 1940s
- PM Magazine, a news programme broadcast in the US from 1976 to 1991
- Perry Mason, a fictional defense attorney
- Popular Mechanics, an American magazine devoted to science and technology
- The Peoples of Middle-earth by Christopher Tolkien
- Martin PM, a version of the Naval Aircraft Factory PN flying boat
- Paris Metro
- Pere Marquette Railway
- Toyota PM, a concept car
- PM-38, Soviet light mortar
- PM-43, Finnish anti-personnel mine
- PM-63 RAK, Polish submachine gun
- PM-60, East German anti-tank mine
- PM-68, Finnish anti-personnel mine
- PM-79, Bulgarian anti-personnel mine
- PM-84 Glauberyt, Polish submachine gun
- PM md 96, Romanian submachine gun
- Makarov PM (Pistolet Makarova), a 1940’s, Soviet pistol
- Minebea PM-9, Japanese submachine gun
- 2PM, a seven-member boy band from South Korea
- 4 P.M., an American male R&B group
- P.M. Dawn, American hip-hop act
- PM-1, American nuclear reactor.
- Prime minister, the most senior minister of a cabinet
- Preventive maintenance, a job for fault prevention during machine executes before occurring some problems.
- Pontifex maximus, the high priest of the Ancient Roman College of Pontiffs
- Postmaster, the head of an individual post office
- Palace Museum, a large art museum housed in the Forbidden City in Beijing
- Palm mute, in guitar tablature
- Polar Medal, a medal awarded by the Sovereign of the United Kingdom
- Saint-Pierre and Miquelon: ISO 3166-1 alpha-2 country code
Lastly, PM in Malaysia also known as Perempuan Mongolia… opps…