1. Any worm of the Chaetognatha; transparent marine worm with horizontal lateral and caudal fins and a row of movable curved spines at each side of the mouth
   "The chaetognath darted through the water column, hunting smaller plankton";
   - arrowworm

Derived forms: chaetognaths

Type of: worm

Part of: Chaetognatha, phylum Chaetognatha

Encyclopedia: Chaetognath