- Noun - 1. a cavity or space in something; "hunger had caused the hollows in their cheeks"- 2. a small valley between mountains; "he built himself a cabin in a hollow high up in the Appalachians"- 3. a depression hollowed out of solid matter 
- Verb - 1. remove the inner part or the core of; "the mining company wants to excavate the hillsite"- 2. remove the interior of; "hollow out a tree trunk"
- Adjective - 1. not solid; 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"- 2. deliberately deceptive; "hollow (or false) promises""false pretenses"- 3. as if echoing in a hollow space; "the hollow sound of footsteps in the empty ballroom"- 4. devoid of significance or point; "empty promises""a hollow victory""vacuous comments"