Look up: stpd

1. STPD
   Symbol indicating that a gas volume has been expressed as if it were at standard temperature (0°C), standard pressure (760 mm Hg absolute), dry; under these conditions a mole of gas occupies 22.4 liters. ... (05 Mar 2000) ...
   Found on http://www.mondofacto.com/facts/dictiona
   
   
2. STPD
   standard temperature and pressure, dry; denoting a volume of dry gas at 0° C and a pressure of 760 mm Hg.
   Found on http://www.encyclo.co.uk/local/21001
   
   
3. STPD
   Type: Symbol Definitions: 1. Abbreviation indicating that a gas volume has been expressed as if it were at standard temperature (0°C), standard pressure (760 mm Hg absolute), and dry; under these conditions a mole of gas occupies 22.4 L.
   Found on http://www.medilexicon.com/medicaldictio