From Longman Dictionary of Contemporary Englishinversionin‧ver‧sion /ɪnˈvɜːʃən $ -ˈvɜːrʒən/ noun [countable, uncountable]  1 formalOPPOSITE/REVERSE the act of changing something so that it is the opposite of what it was before, or of turning something upside down  (=the bottom is on the top and the top is on the bottom)2 technicalHEM a type of weather condition in which the air nearest the ground is cooler than the air above it 
                                                    
                                                
