hollow

nouns

a cavity or space in something
"hunger had caused the hollows in their cheeks"
is a type of (narrower)
space that is surrounded by something
a small valley between mountains
"he built himself a cabin in a hollow high up in the Appalachians"
a depression hollowed out of solid matter

verbs

remove the inner part or the core of
"the mining company wants to excavate the hillside"
remove the interior of
"hollow out a tree trunk"

adjectives

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"
is derived from
antonym
is similar to
being or suggesting a cavern
"vast cavernous chambers hollowed out of limestone"
is similar to
having a sunken area
"hunger gave their faces a sunken look"
is similar to
hollow and tube-shaped like a reed
is similar to
constituting a tube; having hollow tubes (as for the passage of fluids)
see also
holding or containing nothing
"an empty glass"; "an empty room"; "full of empty seats"; "empty hours"
is an attribute of
state of having the interior filled with matter
as if echoing in a hollow space
"the hollow sound of footsteps in the empty ballroom"
is similar to
having a tendency to reverberate or be repeatedly reflected
"a reverberant room"; "the reverberant booms of cannon"
devoid of significance or point
"empty promises"; "a hollow victory"; "vacuous comments"
is derived from