/ɪnˈkluːd/
[verb] To contain something or someone as part of a larger group or whole. If a list or collection includes something, that thing is one of its parts.
The word 'include' literally meant to shut something inside — like locking it in a room.
The story of 'include' begins in ancient Rome, with a Latin verb of satisfying simplicity: *includere*, meaning 'to shut in' or 'to enclose.' This verb was built from two clear pieces — the prefix *in-*, meaning 'into' or 'within,' and *claudere*, meaning 'to shut' or 'to close.' The physical image behind it was concrete and immediate: a door being pushed closed, something trapped or contained within walls.
The root *claudere* is one of the great hidden engines of the English language, quietly powering dozens of words we use every day. Through Latin *claudere*, the chain runs in several directions: Latin *claudere* → Old French *clore* → Middle English *close*, giving us the ordinary word 'close.' Latin *claudere* also became *cludere* in compounds, which passed into English words like 'exclude' (to shut out), 'preclude' (to shut off in advance), 'occlude' (to block or close off), and 'seclude' (to shut away in private). Every one of these words carries that same ancient Roman door at its heart.
The word entered English in the 15th century, drawn directly from classical Latin *includere*, during a period when English writers and scholars were borrowing heavily from Latin to build a more precise and formal vocabulary. At first, 'include' kept close to its physical roots and could mean to literally enclose or confine something — a prisoner might be included within a prison, or an animal within a pen. The idea of containment was spatial and real, not abstract.
Over time, the meaning softened and broadened. By the 16th and 17th centuries, 'include' had moved away from walls and locks and begun to describe intellectual or categorical containment — the idea that one concept, group, or list could hold another within it. A set of rules might include certain exceptions. A dinner invitation might include a guest. The physical door had become a conceptual boundary, and 'include' had made the journey from architecture to logic.
What makes 'include' particularly interesting is its relationship with its twin and opposite, 'exclude' — from Latin *excludere*, built from *ex-* (out) and *claudere* (to shut). These two words have been mirror images since Latin itself, and together they map one of the most fundamental human experiences: the drawing of a line between what belongs inside a group and what is left outside. In social history, questions of inclusion and exclusion have defined communities, nations, and identities. The little verb carries remarkable moral weight for something that began as a description of closing a door.
Today, 'include' is one of the most common verbs in the English language, appearing in everything from shopping lists to legal contracts to conversations about social justice. Its meaning has expanded so far from its origins that few people who use it picture anything like a door being shut. Yet the Latin root *claudere* still lives inside it, as patient and permanent as a lock that has never been touched.