Translation guide
The part of the arm between the shoulder and the elbow. In Japanese, this is most commonly expressed with the word 二の腕 (にのうで), but other terms exist depending on context.
Referring to the upper arm as a body part in everyday conversation.
The most common and natural word for 'upper arm' in Japanese. Used in daily life, health, and beauty contexts.
二の腕を細くする運動を教えてください。
Please tell me exercises to slim down the upper arms.
彼女は二の腕にタトゥーを入れている。
She has a tattoo on her upper arm.
Anatomical/medical term for 'upper arm'. Used in formal or technical contexts.
上腕二頭筋は力こぶを作る筋肉です。
The biceps brachii is the muscle that makes the bulge.
General word for 'arm'. Can refer to the whole arm or upper arm depending on context. Use when the distinction is clear.
腕が太くて困っている。
I'm bothered by my thick arms.
Talking about sleeve length, arm circumference, or fit of clothing.
Refers to the circumference of the upper arm, often used in tailoring or fitness.
このジャケットは二の腕周りがきつい。
This jacket is tight around the upper arms.
Sleeve length. Not specifically 'upper arm', but used when discussing how far a sleeve extends on the arm.
袖丈が短すぎて二の腕が出てしまう。
The sleeves are too short and my upper arms show.
Expressions involving the upper arm in a non-literal sense.
Literally 'to stroke one's upper arm', an idiom meaning to be proud of one's strength or to show off one's muscles.
彼は力自慢で、よく二の腕を撫でている。
He's proud of his strength and often strokes his upper arm.