The Collaborative International Dictionary
                    Synteretic
                    
                        
                
                                                                    Synteretic \Syn`te*ret"ic\, a. [Gr. ?.] (Med.) Preserving health; prophylactic. [Obs.]
Wiktionary
                    synteretic
                    
                        
                
                                                                    a. (context medicine obsolete English) Preserving health; prophylactic.