This is the 1726th most frequent Japanese word.
カッコ
"カッコ" means "parentheses" or "brackets" in English. It can also colloquially mean "cool" or "stylish."
In this sentence, 'カッコいい' is used as a colloquial expression meaning 'cool' or 'stylish', often used to describe a person's appearance or the aesthetic appeal of objects.
彼の車はとてもカッコいいですね。
His car is really stylish, isn't it?
Here, 'カッコ' refers to 'parentheses', used in mathematical expressions for clarity and operational grouping.
数学でカッコを使う方法を学びました。
I learned how to use parentheses in mathematics.
In this usage, 'カッコつける' is a phrase meaning 'to try to look cool' or 'to show off'. It describes behavior aimed at impressing others.