/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.