凹窝,空旷,空虚
Hollowness \Hol"low*ness\, n. 1. State of being hollow. --Bacon. 2. Insincerity; unsoundness; treachery. --South.
hollowness n 1: the state of being hollow: having an empty space within [ant: {solidity}] 2: the property of having a sunken area