A soldier was an individual who fought as part of an organised land-based armed force.
Bryn Lavers was a soldier for the Fifth Axis. He was ordered to spy on Bernice Summerfield. He was later murdered by the robot waiters at the pub where Benny stayed on Daglan Straklant's orders, when he couldn't remove his disguise as a robot waiter. (PROSE: The Doomsday Manuscript)
The Twelfth Doctor rejected Journey Blue's request to travel with him as she was a soldier. When Journey pointed out that the Doctor didn't like soldiers, he retorted "you're the ones with the guns; you don't have to be liked." (TV: Into the Dalek)
In the 1st century BC, it was common practice for Roman soldiers to rape women before killing them in order to instill fear in the places they conquered. Erimem killed several Roman soldiers and later expressed to Andy Hansen that if she hadn't, they likely would have raped her and Andy before murdering them. Later, Anna Whitaker was nearly raped by drunk men because she had turned down the lewd advances of one man the previous night. (PROSE: The Last Pharaoh)