ボールペン（ボールペン、boーrupen）
- ballpoint pen

ボールペン (bōrupen) is the Japanese word for "ballpoint pen". It's a writing instrument that uses a small ball bearing at its tip to dispense ink onto paper. These pens are common and widely used for writing, drawing, and sketching.

⚫︎新しいボールペンを買いました。 Translation: I bought a new ballpoint pen. ⚫︎ボールペンで名前を書いてください。 Translation: Please write your name with a ballpoint pen.

⚫︎ You can use ボールペン in any situation where you would use a ballpoint pen in English. ⚫︎ It's used when you want to specify you are using a ballpoint pen, rather than another type of pen or writing instrument.

⚫︎ ボールペン is written in katakana, which is used for loanwords (words borrowed from other languages). ⚫︎ It is always written in katakana. There are no kanji for ボールペン.

⚫︎ There are no direct synonyms in Japanese, as ボールペン precisely refers to a ballpoint pen. Other types of pens like a fountain pen 万年筆 (mannenitsu) or a felt-tip pen サインペン (sainpen) would be different, though.

⚫︎ There is no direct antonym, as it depends on the context. If you are contrasting writing implements, then other types of pens such as fountain pens or pencils could be considered antonyms.

このボールペンはインクが出ない。 ・Translation: This ballpoint pen doesn't have any ink. ・Explanation: This sentence describes that the ボールペン is not working.

ボールペンで宿題をしました。 ・Translation: I did my homework with a ballpoint pen. ・Explanation: This sentence describes the writing tool used for homework.

⚫︎ The word ボールペン is a combination of the English words "ball" and "pen", directly reflecting the pen's core component. ⚫︎ The "ball" refers to the ball bearing in the tip, and "pen" refers to the writing instrument itself.