Initially locked and secure (4)
I believe the answer is:
land
'secure' is the definition.
(I've seen this in other clues)
'initially locked and' is the wordplay.
'initially' suggests taking the first letters.
The initial letter of 'locked' is 'l'.
'l'+'and'='LAND'
(Other definitions for land that I've seen before include "Ground; country" , "Put in" , "See 5" , "Take catch" , "Part of Germany" .)