noun
                                                a cavity or space in something
                                                
                                                                                                Examples
                                                
                                                                                                        - hunger had caused the hollows in their cheeks
 
                                                                                        
                                                noun
                                                a small valley between mountains
                                                                                                Synonyms
                                                
                                                
                                                                                                Examples
                                                
                                                                                                        - he built himself a cabin in a hollow high up in the Appalachians
 
                                                                                        
                                                noun
                                                a depression hollowed out of solid matter
                                                                                                Synonyms
                                                
                                                
                                                                                             
                                                                                        
                                                verb
                                                remove the inner part or the core of
                                                                                                Synonyms
                                                
                                                
                                                                                                Examples
                                                
                                                                                                        - the mining company wants to excavate the hillside
 
                                                                                        
                                                verb
                                                remove the interior of
                                                                                                Synonyms
                                                
                                                                                                                                                                        hollow out
                                                                                                                                                                                                                                core out
                                                                                                                                                            
                                                
                                                                                                Examples
                                                
                                                                                                        - hollow out a tree trunk
 
                                                                                        
                                                adjective
                                                not solid
                                                
                                                                                                Examples
                                                
                                                                                                        - having a space or gap or cavity
- a hollow wall
- a hollow tree
- hollow cheeks
- his face became gaunter and more hollow with each year
 
                                                                                        
                                                adjective
                                                as if echoing in a hollow space
                                                
                                                                                                Examples
                                                
                                                                                                        - the hollow sound of footsteps in the empty ballroom
 
                                                                                        
                                                adjective
                                                devoid of significance or force
                                                                                                Synonyms
                                                
                                                
                                                                                                Examples
                                                
                                                                                                        - empty promises
- a hollow victory
- vacuous comments
 
                                                                                        
                                                adjective
                                                lacking in substance or character
                                                
                                                                                                Examples
                                                
                                                                                                        - a hollow person