Break tile under ground (9)
I believe the answer is:
interlude
'break' is the definition.
(thesaurus)
'tile under ground' is the wordplay.
'ground' indicates an anagram (grind the letters ).
'tile'+'under'='tileunder'
'tileunder' anagrammed gives 'INTERLUDE'.
(Other definitions for interlude that I've seen before include "Intermission, break" , "Break in performance" , "Short performance during an interval" , "Hiatus" , "Breathing space" .)