countable, uncountable] a system, especially in a society or an organization, in which people are organized into different levels of importance from highest to lowest (Oxford)
[countable + singular or plural verb] the group of people in control of a large organization or institution (Oxford)
a system in which people or things are arranged according to their importance (Cambridge)
She's quite high up in the management hierarchy. (Oxford)
It was on orders from the party hierarchy that she dropped the investigation. (Oxford)
Some monkeys have a very complex social hierarchy. (Cambridge)
management hierarchy
party hierarchy
social hierarchy
Ranking
Position
Ungraded
Unordered
Hierarchically
Hierarchical