The story
Apparently from the use of cards with a rank of 10 in early card games.
First known use, by meaning
- 15th–17th c. A bold front, an instance of standing one's ground.
Etymology from Wiktionary, CC BY-SA 4.0.
card of ten
Today it means: A bold front, an instance of standing one's ground. Full definition →
First used 15th–17th c.