The term 'duration of service' can be summarized as the length of time an individual has been employed in a particular job. The crossword solution for this term is 'LONGEVITY, ' which refers to the length of time someone has been in a job or profession. This could refer to the amount of years, months, or days that someone has been employed in a certain position. LONGEVITY is often seen as a sign of dedication and commitment to a job, and is often rewarded with promotions or other benefits.