MOS

from The Collaborative International Dictionary of English v.0.48

Mos \Mos\, n.,
   sing. of {Mores}. [Rare]
   [Webster 1913 Suppl. +PJC]

from The Collaborative International Dictionary of English v.0.48

Mores \Mo"res\ (m[=o]"r[=e]z), n. pl.; sing. {Mos} (m[=o]s).
   [L.]
   Customs; habits; esp., moral customs conformity to which is
   more or less obligatory; customary law. [singular is rarely
   used]
   [Webster 1913 Suppl. +PJC]

from The Free On-line Dictionary of Computing (8 July 2008)

Metal Oxide Semiconductor
MOS

   <electronics> (MOS) The three materials used to form a {gate}
   in the most common kind of {Field Effect Transistor} - a
   {MOSFET}.

   [Other MOS devices?]

   (1996-05-27)

from V.E.R.A. -- Virtual Entity of Relevant Acronyms (June 2006)

MOS
       Master Operating System (OS, Varian)

from V.E.R.A. -- Virtual Entity of Relevant Acronyms (June 2006)

MOS
       Metal Oxide Semiconductor (IC)

from V.E.R.A. -- Virtual Entity of Relevant Acronyms (June 2006)

MOS
       Minimum Operating System (OS, UNIVAC 9200, UNIVAC 9300)

from V.E.R.A. -- Virtual Entity of Relevant Acronyms (June 2006)

MOS
       Multiprogramming Operating System (OS, NCR)