What does biff stand for in the Army?

The Origins and Meaning of "Biff" in Military Slang

Every subculture develops its own distinct vocabulary, and the British Army is certainly no exception. Among the vast array of slang terms tossed around the barracks, the word "biff" (or "biffer") holds a very specific, and usually less-than-enviable, meaning. If someone is labeled a biff, it means they are perceived as someone who spends an excessive amount of time on sick notes or light duties.

In military culture, physical fitness, resilience, and pulling your own weight are paramount. When a soldier is placed on a medical restriction—historically referred to as being on "chit"—they are temporarily excused from certain duties, marches, or training exercises. While genuine injuries are a reality of service, those who seem to constantly find themselves with a medical excuse can quickly earn the reputation of being a biff.

The term itself is believed by many to have originated as a loose acronym, often cited as standing for "Broke In For Free" or related to being medically "unfit." Over time, however, it evolved past its literal origins to become a standard piece of soldier slang. It is used both as a noun to describe the person and as a verb—"biffing about"—to describe the act of avoiding hard work or training.

While often used in a lighthearted, teasing manner among peers, being called a biff carries a subtle undercurrent of social pressure. In an environment where teamwork is vital, the slang serves as a cultural mechanism, encouraging soldiers to recover quickly and get back into the formation with their comrades.