Chief of the admin section (4)
I believe the answer is:
head
'chief' is the definition.
(I know that chief can be written as head)
'of the admin section' is the wordplay.
'section' says the answer is hidden in the clue.
'HEAD' is hidden in the letters of 'of the admin'.
(Other definitions for head that I've seen before include "Chief; go first" , "bean" , "Leader; water pressure" , "Beer foam; front" , "Skull" .)