A firefighter was an individual trained in fighting fires.
San Francisco firefighter, 1893
In 1893, as Data walked down Putney, a firefighter attached to No. 5 Fire House was doing maintenance on a fire engine. (TNG: "Time's Arrow")
The San Francisco Register, 1986
In 1986, a photo of firefighters fighting a fire at the Fairmont Hotel was on the front page of the San Francisco Register. (Star Trek IV: The Voyage Home)
The caption to the photo identified the firefighters as "firemen".
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