'backswordman' originates from English, specifically the compound 'backsword' + 'man', where 'backsword' referred to a single-edged sword and 'man' meant a person or soldier.

'backsword' is a compound from Middle/Early Modern English combining 'back' (Old English 'bæc') and 'sword' (Old English 'sweord'); the formation 'backswordman' arose in Early Modern English to denote a man armed with such a weapon and was used in 17th–18th century military descriptions.

Initially it meant 'a man armed with a backsword' and its core meaning has remained the same; the term has become archaic and is largely replaced by 'swordsman' or more specific military terms in modern usage.