:BLT: /B-L-T/, /bl*t/ or (rarely) /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'.