1
                           general:: 
                            Phrase(s): *in force
1. [of a rule or law] currently valid or in effect. (*Typically: be ~.)  •  Is this rule in force now?  •  The constitution is still in force. 2. Fig. in a very large group. (*Typically: arrive ~; attack ~.)  •  The entire group arrived in force.  •  The mosquitoes will attack in force this evening.
                        
                        
 
                        
                            McGrawhill's American Idioms And Phrasal Verbs
                        
                        
                    
                    
                        2
                           general:: 
                            1. In full strength, in large numbers, as in Demonstrators were out in force. This usage originally alluded to a large military force. [Early 1300s] 2. Operative, binding, as in This rule is no longer in force. This usage originally alluded to the binding power of a law. [Late 1400s]
                        
                        
 
                        
                            American Heritage Idioms