seniority

Etymology

From Middle English senyoryte, from Medieval Latin senioritas, from Latin senior (“elder”).

noun

1. A measure of the amount of time a person has been a member of an organization, as compared to other members, and with an eye towards awarding privileges to those who have been members longer.
   It's an old-fashioned company, with parking spaces and other perks doled out on the basis of seniority.