seniority
n. uncountablen. the state of being older or having a higher rank than someone else. In a job, it usually means you have worked there for a long time.
n. the state of being higher in rank or status than others, typically by virtue of longer service. Often determines priority in professional contexts such as promotions or scheduling.
The company promotes employees based on their seniority.
Because she had the most seniority in the department, she was allowed to choose her vacation dates first.
While merit-based systems are becoming more common, many traditional organizations still rely on seniority to establish the hierarchy and distribute internal responsibilities among the staff.
Uncountable in its general sense; often used with the preposition 'over' to show comparison between people.