1. The aquatic larva of a dobsonfly, having a long dark body with pincers and gill filaments, found in fast-moving streams and used as fishing bait.
Usage: chiefly North American; also called alderfly larva

Examples

• Anglers prize hellgrammites as bait for catching bass and catfish.
• The hellgrammite crawled along the rocky stream bottom, searching for small prey.
• You can find hellgrammites under rocks in cold, clean streams.
• The fisherman flipped over a stone and spotted a large hellgrammite.
• Hellgrammites are an important food source for many freshwater fish species.
• The larva will eventually transform into a dobsonfly after leaving the water.