tickinggerund / present participle Used attributively to describe something that emits a ticking sound or is about to cause imminent effect (e.g., ‘a ticking clock’, ‘a ticking bomb’).
Definitions
Emitting a short, sharp, repetitive sound like that of a clock or watch. She lay awake listening to the ticking clock on the wall.
Imminently dangerous or liable to have an explosive or serious effect if not dealt with. The report warned of a ticking bomb in the nation’s pension system.