head noun definition in Job titles topic from the Oxford Advanced Learner's Dictionary

head

 noun: Job titles topic
[countable, uncountable] the person in charge of a group of people or an organization the heads of government/state She resigned as head of department. the crowned heads (= the kings and queens) of Europe the head gardener/waiter, etc. (British English) the head boy/girl (= a student who is chosen to represent the school)