Ballpoint pen and Ball point pen

Ballpoint pen noun - A pen that has a small metal ball as the point of transfer of ink to paper.

Ball point pen and ballpoint pen are semantically related. In some cases you can replace phrase "Ball point pen" with "Ballpoint pen", this phrases are similar.

Ballpoint pen and ball point pen are semantically related. You can use "Ballpoint pen" instead a noun phrase "Ball point pen".