from The American Heritage® Dictionary of the English Language, 5th Edition.
- noun One of a set of three paired appendages on the thorax of a decapod crustacean, located just posterior to the maxillae and used in feeding.
from The Century Dictionary.
- noun In Crustacea, a foot-jaw or gnathopodite; one of the several limbs which are so modified as to partake of the characters of both jaw and foot, serving for the purpose of both mastication and locomotion.
from the GNU version of the Collaborative International Dictionary of English.
- noun (Zoöl.) One of the mouth appendages of Crustacea, situated next behind the maxillæ. Crabs have three pairs, but many of the lower Crustacea have but one pair of them. Called also
jawfoot, and foot jaw.
from Wiktionary, Creative Commons Attribution/Share-Alike License.
- noun One of the
appendageson the heads of some crustaceansbehind the maxillae, used for feeding.
from The American Heritage® Dictionary of the English Language, 4th Edition
The first thoracic leg is modified into a feeding appendage ( "mouth part"), the maxilliped, while the other seven pairs of thoracic legs are used for movement.
Thus when a wave of water escapes from the branchial cavity, it immediately becomes diffused in this network of hairs and then again conveyed back to the branchial cavity by vigorous movements of the appendage of the outer maxilliped which works in the entrant fissure.
High-speed video footage of maxilliped movement is available here: