ボールペン
ボールペン · boorupen · JLPT N5 · noun
pen
🖊️ ボール + ペン = ball + pen, borrowed straight from English
A katakana loanword: booru is English ball and pen is pen, so boorupen is just ball-pen with Japanese vowels added. The long oo in ボール is marked by the ー bar. Say ball-pen slowly with an extra u and you have it.