f'nar / F'Nar / fNAR / FNAR / F-Nar / F-nar ...
You act like a total idiot just because you felt like it and no one even said anything to you.
He started dancing in the hallway for no apparent reason. No one asked him to.
She yelled at the teacher for no apparent reason. It was just math class.
He turned on the radio in the middle of the night for no apparent reason. It was super loud.