noun
                                                following the third position
                                                
                                                                                                Examples
                                                
                                                                                                        - number four in a countable series
 
                                                                                        
                                                noun
                                                one of four equal parts
                                                                                                Synonyms
                                                
                                                
                                                                                                Examples
                                                
                                                                                                        - a quarter of a pound
 
                                                                                        
                                                noun
                                                the musical interval between one note and another four notes away from it
                                                
                                                                                             
                                                                                        
                                                adjective
                                                coming next after the third and just before the fifth in position or time or degree or magnitude
                                                                                                Synonyms
                                                
                                                
                                                                                                Examples
                                                
                                                                                                        - the quaternary period of geologic time extends from the end of the tertiary period to the present
 
                                                                                        
                                                adverb
                                                in the fourth place
                                                                                                Synonyms
                                                
                                                
                                                                                                Examples
                                                
                                                                                                        - fourthly, you must pay the rent on the first of the month