IPA: /ˈriːɪnæktər/
KK: /ˈriːɪnæktər/
A person who acts out or performs a historical event, often in costume, to recreate and educate others about that time period.
The reenactor dressed in a Civil War uniform to participate in the historical event.
Reenactor → It is formed from "re-" (meaning again) and "enact" (from Latin "enactare", meaning to perform or put into effect) and the suffix "-or" (meaning one who). The word "reenactor" refers to one who performs or acts out again, typically in a historical context.
Think of someone who performs or acts out a scene 'again' ('re-') — that's why a reenactor is someone who reenacts events.