V.E.R.A. -- Virtual Entity of Relevant Acronyms (February 2016):

IRQ
       Interrupt ReQuest


The Free On-line Dictionary of Computing (30 December 2018):

interrupt request
IRQ

   (IRQ) The name of an input found on many processors which
   causes the processor to suspend normal instruction execution
   temporarily and to start executing an interrupt handler
   routine.  Such an input may be either "level sensitive" -
   the interrupt condition will persist as long as the input is
   active or "edge triggered" - an interrupt is signalled by a
   low-to-high or high-to-low transition on the input.  Some
   processors have several interrupt request inputs allowing
   different priority interrupts.

   (1994-12-08)