The Collaborative International Dictionary
                    Commutual
                    
                        
                
                                                                    Commutual \Com*mu"tu*al\ (?; 135), a. [Pref. com- + mutual.] Mutual; reciprocal; united. [R.]
There, with commutual zeal, we both had strove. 
--Pope.
Wiktionary
                    commutual
                    
                        
                
                                                                    adv. (context obsolete English) reciprocally