The Collaborative International Dictionary
                    Metabranchial
                    
                        
                
                                                                    Metabranchial \Met`a*bran"chi*al\, a. [Meta- + branchial.] (Zo["o]l.) Of or pertaining to the lobe of the carapace of crabs covering the posterior branchi[ae].
Wiktionary
                    metabranchial
                    
                        
                
                                                                    a. (context zoology English) Of or pertaining to the lobe of the carapace of crabs covering the posterior branchiae.