Yegg's target (4)
I believe the answer is:
'yegg's target' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for safe that I've seen before include "Uninjured, secure" , "Uninjured; excellent; lockable cabinet" , "Cash-box" , "Locked store for money etc" , "Harmless" .)