trap

trap  1. n. A program interrupt, usually an interrupt caused
   by some exceptional situation in the user program.  In most cases,
   the OS performs some action, then returns control to the program.
   2. vi. To cause a trap.  "These instructions trap to the
   monitor."  Also used transitively to indicate the cause of the
   trap.  "The monitor traps all input/output instructions."

   This term is associated with assembler programming (`interrupt'
   or `exception' is more common among {HLL} programmers) and
   appears to be fading into history among programmers as the role of
   assembler continues to shrink.  However, it is still important to
   computer architects and systems hackers (see {system},
   sense 1), who use it to distinguish deterministically repeatable
   exceptions from timing-dependent ones (such as I/O interrupts).