Definition of "Hollow" :
noun: a depression hollowed out of solid matter
noun: a small valley between mountains
"He built himself a cabin in a hollow high up in the Appalachians."
noun: a cavity or space in something
"Hunger had caused the hollows in their cheeks."
verb: remove the interior of
"Hollow out a tree trunk."
verb: remove the inner part or the core of
adjective: lacking in substance or character
"A hollow person."
adjective: devoid of significance or force
"A hollow victory."
adjective: as if echoing in a hollow space
"The hollow sound of footsteps in the empty ballroom."
adjective: not solid; having a space or gap or cavity
"A hollow wall."