A commissary is a place or service that sells food and other essentials to people who are away from home for work or travel. It's like a convenient store.
You might hear about a military base having a commissary, which means soldiers can buy basic groceries there instead of going off-base. This is helpful because they often have limited time and money during their deployments. Some prisons also have commissaries where inmates can purchase personal items using the funds in their accounts. In both cases, the goal is to provide easy access to basic necessities for people who are stuck away from home.
A store primarily serving persons in an institution, most often soldiers or prisoners.
