Presumably the boss has one!
I believe the answer is:
head
'one' is the definition.
(thesaurus)
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for head that I've seen before include "Leader; water pressure" , "Lead - school principal" , "See 14" , "See 25" , "''and still the wonder grew / That one small ... could carry all he knew'' (Goldsmith)" .)