A popular term, thought to be initially coined in 2008 at a donut shop in the Maltese village of San Gwann, indicating an incognito or underhanded act. Its ever-evolving versality has contributed to its rapid adoption across the Maltese islands. Both a verb and an adjective.
John met a girl on Tinder. He went on a date with her, without telling his friends. John went on a secret service date.
Sarah was drinking at a bar and wanted to leave to buy brocolli, but was too shy to tell her friends. She snuck away and bought her broccoli. That made her brocolli, secret service brocolli.