intransitive verb. 
                    To commit the first act of hostility or offense; to begin a quarrel or controversy; to make an attack; -- with on.
                  
                
                  
                    intransitive verb. 
                    take the initiative and go on the offensive, as in a game.
                  
                
                  
                    transitive verb. 
                    To set upon; to attack.
                  
                
                  
                    noun. 
                    Aggression.