Definition of hierarchy noun from the Oxford Advanced Learner's Dictionary

Academic

hierarchy

noun
ˈhaɪərɑːki
 
; ˈhaɪərɑːrki
 
plural hierarchies
 
1 [countable, uncountable] a system, especially in a society or an organization, in which people are organized into different levels of importance from highest to lowestthe social/political hierarchyShe's quite high up in the management hierarchy.2 [countable + singular or plural verb] the group of people in control of a large organization or institution3 [countable] (formal) a system that ideas or beliefs can be arranged intoa hierarchy of needs