ballpoint pen

US /ˈbɑːl.pɔɪnt ˌpen/
UK /ˈbɑːl.pɔɪnt ˌpen/
"ballpoint pen" picture
1.

długopis

a pen with a writing point that consists of a small metal ball that rotates in a socket and feeds ink from a reservoir

:
Please sign the document with a ballpoint pen.
Proszę podpisać dokument długopisem.
I prefer writing with a ballpoint pen over a fountain pen.
Wolę pisać długopisem niż piórem wiecznym.