Hollow liquid dispenser with nothing in (10)
I believe the answer is:
depression
'hollow' is the definition.
(thesaurus)
'liquid dispenser with nothing in' is the wordplay.
'liquid' indicates anagramming the letters.
'with' means one lot of letters goes inside another.
'nothing in' becomes 'o' (I've seen this in other clues).
'dispenser' is an anagram of 'depressin'.
'depressin' placed around 'o' is 'DEPRESSION'.
(Other definitions for depression that I've seen before include "valley" , "despair" , "Nineteen twenty nine financial slump" , "gloom" , "Blues" .)