Ichidan verb, Intransitive verb
to act timid; to show diffidence; to be hesitant; to appear embarrassed; to look ashamed
usu. with negative sentence
そんな事実にまったく悪びれることなく、千歳は今日も元気に過ごしております。Without flinching from that fact in the slightest, Chitose is spending today as well in fine spirit.
Also written 悪怯れる【わるびれる】