Duel

This character was involved in a duel.

Historically, a duel is an arranged engagement in combat between two individuals, with matched weapons in accordance with agreed-upon rules.
The duel was based on a code of honour. Duels were fought not so much to kill the opponent as to gain "satisfaction", that is, to restore one's honour (or compete for a woman) by demonstrating a willingness to risk one's life for it, and as such the tradition of duelling was originally reserved for the male members of nobility.

You can also use this trait for non-armed duels (competitive, for example), as long as this is a question of a honour, with possible significant risk to lose something or someone important for a duelist.