Gid

from The Collaborative International Dictionary of English v.0.48

Gid \Gid\, n. [Cf. {Giddy}, a.]
   A disease of sheep, characterized by vertigo; the staggers.
   It is caused by the presence of the C?nurus, a larval
   tapeworm, in the brain. See {C?nurus}.
   [1913 Webster]

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

gid

   1. <operating system> {group identifier}.

   2. <filename extension> {global index}.

   (1997-01-30)

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

GID
       Group ID

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