hollow hollow /ˈhɑːloʊ/

adjective

1. () Devoid of significance or force  ( vacuous , hollow , empty )
   devoid of significance or force
    Empty promises
   empty promises
    A hollow victory
   a hollow victory
    Vacuous comments
   vacuous comments
   
2. () As if echoing in a hollow space  ( hollow )
   as if echoing in a hollow space
    The hollow sound of footsteps in the empty ballroom
   the hollow sound of footsteps in the empty ballroom
   
3. () Not solid; having a space, gap or cavity  ( hollow )
   not solid; having a space, gap or cavity
    A hollow wall
   a hollow wall
    A hollow tree
   a hollow tree
    Hollow cheeks
   hollow cheeks
    His face became gaunter and more hollow with each year
   his face became gaunter and more hollow with each year
   
4. Lacking in substance or character  ( hollow )
   lacking in substance or character
    A hollow person
   a hollow person
   

noun

1. () A cavity or space in something  ( hollow )
   a cavity or space in something
    Hunger had caused the hollows in their cheeks
   hunger had caused the hollows in their cheeks
   
2. () A depression hollowed out of solid matter  ( hollow , hole )
   a depression hollowed out of solid matter
     The bullet left a small hole in the target, marking a perfect bullseye.
   The bullet left a small hole in the target, marking a perfect bullseye.
   
   
3. () A small valley between mountains  ( holler [Informal] , hollow )
   a small valley between mountains
    He built himself a cabin in a hollow high up in the Appalachians
   he built himself a cabin in a hollow high up in the Appalachians
   
   

verb

1. Remove the interior of  ( core out , hollow , hollow out )
   remove the interior of
    Hollow out a tree trunk
   hollow out a tree trunk
   
2. Remove the inner part or the core of  ( dig , excavate , hollow )
   remove the inner part or the core of
    The mining company wants to excavate the hillside
   the mining company wants to excavate the hillside