pretentious or arrogant

りや(きどりや) A poseur or pretentious person:someone who pretends to be someone they’re not.   LIT
(そんだい) An arrogant person – used only about people who outrank you. Usually used like this:尊大な態度
 になってる(いいきになってる) Someone who thinks she all that (only used by young people)
いばってる Arrogant (can be used about someone your own rank – like if you’re complaining about your spouse!)
ってる(xxxぶってる) Same as 気取りや:someone who is pretending to be someone that they are not.
(うぬぼれ) (Lit:‘self love’) someone who brags a lot and is a narcissist.
々しい(ぎょうぎょうしい) Someone who is too formal, pompous, high-falutin’.   LIT
(おうへいな) = arrogant, prone to giving ridiculous orders. You could say that a 尊大 or いばってる person does 横柄 things!