Gunpowder

Part of speech: noun (n.)

1. A black, granular, explosive substance, consisting of an intimate mechanical mixture of niter, charcoal, and sulphur. It is used in gunnery and blasting.

2. Hence, Nov. 5 is known in England as Guy Fawkes Day. -- Gunpowder tea, a species of fine green tea, each leaf of which is rolled into a small ball or pellet.