To be unchivalrous is the exact opposite of being chivalrous.
Lack of Chivalry in the SCA
Unchivalrous behaviour can include rudeness, drunkenness, and offensive behaviour, and is unacceptable in the SCA, as it shows a lack of respect for others and ruins the game for everyone.
On the field, unchivalrous behaviour can include unsafe actions, dishonourable tactics, and dirty tricks.
A reputation for unchivalrous behaviour can be impossible to lose, and is therefore to be avoided at all costs.