fragmentation grenade

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A grenade that scatters shrapnel over a wide area upon explosion.

from the GNU version of the Collaborative International Dictionary of English.

• noun (Mil.) A type of hand grenade designed to burst into multiple fragments upon detonation of the explosive charge; the fragments fly away at high velocity, killing or wounding persons nearby. Contrasted to concussion grenade. The common type of fragmentation grenade used by the American military was sometimes jocosely referred to as a pineapple from its reticulated surface appearance, resembling that of the fruit.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun military An anti-personnel weapon, thrown or otherwise propelled, designed to disperse shrapnel upon exploding.