chelicera

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. Either of the first pair of fanglike appendages near the mouth of an arachnid, such as a spider, often modified for grasping and piercing.

Century Dictionary and Cyclopedia

1. n. One of the anterior pair of appendages of a scorpion; a short, three-jointed organ ending in a prehensile claw. See cut under scorpion.
2. n. The corresponding organ in a spider, which terminates in a sharp joint folding down on the preceding one like the blade of a pocket-knife on the handle, and having at its extremity the opening of a poison-gland. This gland is not found in the cheliceræ of the scorpions. These organs are supposed by some naturalists to be the homologues of the antennæ of insects, but others believe that they correspond to the mandibles.
3. n. Also in English form chelicere.

Wiktionary

1. n. zoology One of the prehensile claws found on the proboscises of chelicerates (spiders and scorpions).

GNU Webster's 1913

1. n. (Zoöl.) 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.

WordNet 3.0

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