Burrowing insectivore (4)
I believe the answer is:
mole
'burrowing insectivore' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for mole that I've seen before include "Subterranean mammal" , ""Gentleman in black velvet''" , "A spy within an organisation" , "Breakwater; naevus" , "digger" .)