A member or supporter of the Parliamentary party in the English Civil War.
- ‘It's a 14th Century Norman castle, which gained fame as the last Irish stronghold to submit to Oliver Cromwell's Roundheads.’
- ‘The film, though set during the English Civil War, ignores conflicts between Cavaliers and Roundheads to dwell on the seedy lawlessness sown by the war.’
- ‘Inevitably a student will want to know how Jefferson could defend revolution in the Declaration; how did he succeed where the Roundheads had failed?’
- ‘Religion and geopolitics gave the nation a context, an idea that the rebels' vigilance matched that of Corsican freedom fighters, English Roundheads, or even Mosaic Hebrews.’
- ‘After changing hands at least half a dozen times during the English Civil War, Scarborough Castle has once again found the Roundheads at the gates.’
So named because of the short-cropped hairstyle of the Puritans, who formed an important element in the party.