Caught greeting in cavern (4)
I believe the answer is:
cave
'cavern' is the definition.
(thesaurus)
'caught greeting' is the wordplay.
'caught' becomes 'c' (cricket abbreviation).
'greeting' becomes 'ave' (I've seen this before).
'c'+'ave'='CAVE'
'in' is the link.
(Other definitions for cave that I've seen before include "Natural underground chamber" , "Hollow in a rock" , "hole" , "Underground enclosure with surface access" , "Subject of speleology" .)