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a. Either of two bony or cartilaginous structures that in most vertebrates form the framework of the mouth and hold the teeth.
b. The mandible or maxilla or the part of the face covering these bones.
c. Any of various structures of invertebrates that have an analogous function to vertebrate jaws.
2. Either of two opposed hinged parts in a mechanical device.
3. jaws The walls of a pass, canyon, or cavern.
4. jaws A dangerous situation or confrontation: the jaws of death.
5. Slang
a. Impudent argument or back talk: Don't give me any jaw.
b. A conversation or chat.
intr.v. jawed, jaw·ing, jaws Slang
1. To talk vociferously; jabber.
2. To talk; converse.

[Middle English jawe, jowe, perhaps from Old French joue, cheek.]

jaw′less adj.


having no jaws or lacking a jaw
ThesaurusAntonymsRelated WordsSynonymsLegend:
Adj.1.jawless - of animals having no jaw
jawed - of animals having jaws of a specified type
References in periodicals archive ?
Mikrostruktura pantsyrya beschelyustnykh pozvonochnykh silura i devona [Mikrostructure of the armour of the jawless vertebrates from the Silurian and Devonian].
Lamprey is an eel-like jawless fish which has the capacity to heal its own spinal cord injuries, so is it possible humans can do the same?
The Kofi Annan commission is proving to be jawless.
Madhav wants the Pakistanis to be jawless because four of them allegedly infiltrated into India.
Hagfishes (Myxinidae) often integrate whole-body knotting movements with jawless biting motions when reducing large marine carcasses to ingestible items.
The creature was probably an ancestor of lampreys, jawless fish that can latch onto prey like a vacuum cleaner hose with teeth, say study coauthor Victoria McCoy of Yale University and colleagues.
sup][13] The MHC locus has been found in all jawed vertebrates, however, the proto-MHC could trace back to the cephalochordate (amphioxus) and jawless vertebrate lineages.
The jawless fish (Class Agnatha) are represented with an interesting study with sea lamprey (Petromyzon marinus) describing the relationship between sperm DNA damage and fertilizing ability [110], while cartilaginous fish (Class Chondrichthyes) are completely unexplored.
autoimmune hepatitis) Present in all eukaryotes Present in jawed vertebrates with (including plants, which, emerging evidence of related however, use different mechanisms immune mechanisms in jawless and molecules in innate immunity) vertebrates and some invertebrates
Over 460 million years ago the first jawless fish swam in shallow seas of what was to become the Appalachian basin of North America.
This was thought to represent a key vertebrate innovation, allowing jawed vertebrates to outcompete their jawless rivals.
Using micron resolution X-ray imaging, they showed how a series of fossils, with a 410 million year old armoured fish called Romundina at its centre, documents the step-by-step assembly of the face during the evolutionary transition from jawless to jawed vertebrates.