Call at first (4)
I believe the answer is:
safe
'call at first' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for safe that I've seen before include "Metal box for storing valuables in" , "Unharmed" , "Uninjured; excellent; lockable cabinet" , "Protected from danger" , "Locked store for money etc" .)