/ˈækʃən/
[noun] The process of doing something, especially to achieve a goal or make something happen. It can also refer to a specific thing that someone does, or the events in a story or film.
Every time you say 'action', you are echoing a Roman law court where lawyers argued about what someone had actually done.
The word 'action' travels to us almost perfectly preserved from Latin, like an insect caught in amber. Its journey begins with the Latin verb 'agere', meaning 'to do', 'to drive', or 'to set in motion'. From this enormously productive root, Latin formed the noun 'actio' (genitive: 'actionis'), which referred specifically to the doing of something — and, very importantly in Roman culture, to a legal process or lawsuit. When a Roman citizen brought an 'actio' against someone, they were formally setting the law in motion against them.
The root 'agere' was one of the most powerful verbs in Latin, and it generated a remarkable family of English words. Latin 'agere' → Old French 'agir' contributed to the English word 'agile'. Latin 'agere' produced the past participle 'actus', which gave us 'act' directly. From the same past participle came 'actor' (one who does or performs), 'active' (in a state of doing), and 'actual' (relating to real deeds or facts). The chain for 'action' itself runs: Latin 'actio' → Old French 'action' → Middle English 'accioun' → Modern English 'action'.
The word entered English in the late 14th century, carried across the Channel by the enormous wave of Old French that flooded English after the Norman Conquest of 1066. For centuries, English courts, churches, and educated writers preferred French and Latin vocabulary, and 'action' arrived as a formal, somewhat elevated term. Its earliest English uses were almost entirely legal — an 'action' was a lawsuit, a claim brought before a judge. You did not take 'action' against your neighbour; you brought an 'action' against them.
Over the following two centuries, 'action' slowly escaped the courtroom. By the 16th century, writers were using it in a broader sense to mean simply something that a person does — any deed, movement, or effort. Shakespeare loved the word and used it in dozens of ways, from military action on the battlefield to the actions of characters on stage. In the theatre, 'action' began to describe the events of a plot, a meaning we still carry today when we talk about the 'action' of a film or novel.
The 20th century gave 'action' an explosive new life. Hollywood cinema turned it into a genre label — 'action film', 'action hero' — and the director's famous cry of 'Action!' became one of the most recognised phrases in popular culture. Meanwhile, the phrase 'take action' became a staple of political speeches and motivational writing, stripping away every last trace of the Latin lawcourt and turning the word into a simple, energetic call to do something. It is a remarkable journey: from a Roman legal procedure, through Norman French courts, through Shakespeare's stage, and all the way to a film set in Hollywood.