Which term describes a stable explosive compound that detonates by percussion?

The term that describes a stable explosive compound which detonates by percussion is "fulminate." Fulminates are sensitive compounds that can respond to impact or friction, making them capable of detonation upon percussion. This property differentiates fulminates from other types of explosives, which may require a booster or additional heat or force to detonate.

In contrast, a detonator refers to a device that initiates an explosion, typically used with explosive materials but not itself classified strictly as a stable explosive compound. A propellant is generally a type of explosive used primarily for propulsion, such as in firearms or rocket motors, and does not necessarily detonate in the same way fulminates do. Blasting agents are explosives that require a booster to detonate and are not sensitive to shock or friction in their uninitiated state, highlighting their lower sensitivity compared to fulminates. Thus, "fulminate" is the accurate term in this context describing a stable explosive that detonates directly from percussion.