ichidan verb, intransitive verb
show off; try to look cool; put on airs
Casual, often mildly critical; used when someone is trying too hard to appear stylish or impressive.
彼はいつもかっこつけて話す。
He always talks trying to sound cool.
そんなにかっこつけなくてもいいよ。
You don't have to try so hard to look cool.