One of the anterior pair of mouth organs, terminated by a pincherlike claw, in scorpions and allied Arachnida. They are homologous with the falcers of spiders, and probably with the mandibles of insects.

The first pair of appendages of a chelicerate arthropod. Originally a short clawed appendage, the chelicerae of many arachnids are highly modified for feeding; in spiders, for instance, they are modified into poisonous fangs.

either of the first pair of fang-like appendages near the mouth of an arachnid; often modified for grasping and piercing