blue jeans
Standard loanword for denim trousers; used like the English term.
彼はいつもブルージーンズをはいている。
He always wears blue jeans.
ジーンズ is a more common, shorter term for jeans in Japanese. ブルージーンズ specifically emphasizes the blue color, but in practice they are often interchangeable.
デニム refers to the denim fabric itself, while ブルージーンズ refers to the garment made from it.
Variant with a middle dot; less common but still seen.
Loanword from English 'blue jeans'.