The willingness to accept and be happy with defeat without fighting for it. People usually think of defeatism as a bad thing, and it is often linked to treason and pessimism. The word “defeatist” is often used in war.
A soldier is a defeatist if they don’t fight because they think they’ll lose or because they don’t think it’s worth fighting for some other reason. The word can also be used in politics, sports, psychology, and philosophy, among other places.