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