godan verb (-ru), intransitive verb
sit upright; sit up straight
Literal meaning: to straighten one's posture from a slouching or relaxed position. Often used when someone corrects their sitting posture.
先生が入ってくると、生徒たちは慌てて居直った。
When the teacher came in, the students hurriedly sat up straight.
godan verb (-ru), intransitive verb
Figurative extension: from a posture of weakness or apology, suddenly adopting a bold, confrontational stance. Often used when someone caught in a fault unexpectedly becomes aggressive or self-righteous.
彼はミスを指摘されると、急に居直って開き直った。
When his mistake was pointed out, he suddenly became defiant and unapologetic.
問い詰められた犯人は居直って、逆に脅し始めた。
The cornered suspect turned defiant and started making threats instead.