1) Aft 2) Pm 3) Stsm 4) Afternoon 1) Autopsy 2) Necropsy 3) Postmeridian 4) Promethium 
Place marker.
(from the article `formal logic`) Probably the best-known axiomatic system for PC is the following one, which, since it is derived from Principia Mathematica, by Whitehead and ...
Atomic number: 61
(Penicillin in Milk ?)
abbreviation: Panama (Central America nation on Caribbean Sea and Pacific Ocean bordered by Costa Rica and Columbia)
abbreviation: or pm Post meridiem, noon til midnight
Abbreviation for prime minister. ...
Performance Management
Personal Message -or- Private Message
Phase Modulationphase modulation
abbreviation: the phenolphthalein alkalinity of the mud reported as the number of milliliters of 0.02 Normal (n/50) add required per milliliter of mud Picometer (10-12 m). 
Post meridiem
Panama
Particulate matter
Product Manager porte mortier (mortar carrier)
Permanent Magnet
or v. Private message, as in, "if interested please PM me" or "Please send me a PM". In BGG it is used to refer to Geekmail--send a private message through geekmail.
acronym: photosynthetic measurements (JGOFS)
premier noun the person who holds the position of head of the government in England
Personnel Manager