Caller sent to vault (6)
![Ross](/clue/static/ross-mug.min.png)
I believe the answer is:
cellar
'vault' is the definition.
(I've seen this before)
'caller sent' is the wordplay.
'sent' indicates anagramming the letters (send can mean to excite or stimulate).
'caller' anagrammed gives 'CELLAR'.
'to' acts as a link.
(Other definitions for cellar that I've seen before include "Storage space, for wine perhaps" , "Place for wine" , "Room at the bottom, maybe for wine" , "Underground area" , "Basement room, wine may be stored there" .)