BLT

from WordNet (r) 3.0 (2006)

BLT
    n 1: sandwich filled with slices of bacon and tomato with
         lettuce [syn: {bacon-lettuce-tomato sandwich}, {BLT}]

from Jargon File (4.4.4, 14 Aug 2003)

BLT
 /B.L.T/, /bl@t/, /belt/, n.,vt.

   Synonym for {blit}. This is the original form of {blit} and the
   ancestor of {bitblt}. It referred to any large bit-field copy or move
   operation (one resource-intensive memory-shuffling operation done on
   pre-paged versions of ITS, WAITS, and TOPS-10 was sardonically
   referred to as "The Big BLT"). The jargon usage has outlasted the
   {PDP-10} BLock Transfer instruction from which {BLT} derives;
   nowadays, the assembler mnemonic {BLT} almost always means "Branch if
   Less Than zero".

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

BLT

   1. /B-L-T/, /bl*t/ or (rarely) /belt/ Synonym for {blit}.
   This is the original form of {blit} and the ancestor of
   {bitblt}.  It refers to any large bit-field copy or move
   operation (one resource-intensive memory-shuffling operation
   done on pre-paged versions of {ITS}, {WAITS} and {TOPS-10} was
   sardonically referred to as "The Big BLT").  The jargon usage
   has outlasted the {PDP-10} BLock Transfer instruction from
   which {BLT} derives; nowadays, the {assembly language}
   {mnemonic} {BLT} almost always means "Branch if Less Than
   zero".

   2. bacon, lettuce and tomato (sandwich).

   [{Jargon File}]

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

BLT
       BLock Transfer