noun
1. : an unyielding, pretentious, or arrogant mood : a high and mighty air or attitude
when he … saw the desperate need for more men, he came down off his high horse — J.F.Dobie
wanted to get on her high horse and treat him as if he were nothing — William Heuman
2. : a sulky or resentful mood, air, or attitude
on your high horse because he didn't praise your mince — Arnold Bennett