Commander The Admiralty accommodates (4)
I believe the answer is:
head
'commander' is the definition.
(I've seen this in another clue)
'the admiralty accommodates' is the wordplay.
'accommodates' indicates the answer is hidden within the clue.
'HEAD' is hidden in the letters of 'the admiralty'.
(Other definitions for head that I've seen before include "Leader; promontory" , "''and still the wonder grew / That one small ... could carry all he knew'' (Goldsmith)" , "Chief; part of body" , "Chief; go first" , "Leader; water pressure" .)