This word is acceptable for play in the US & UK dictionaries that are being used in the following games:

• Lexulous
• Wordscraper
• Wordosaur

n. A BIRO brand ballpoint pen.

n. Any ballpoint pen.

n. Ink from a ballpoint pen.

n. a pen with small metal ball as point of transfer of ink to paper; same as ballpoint pen.

n. a pen that has a small metal ball as the point of transfer of ink to paper

"She seemed to have Lord Mark Malloch-Brown's name biro'ed on her proverbial sleeve."

pen   

ballpoint pen   

ballpoint    ballpoint pen    ballpen   

Hero    Hiro    Nero    Shapiro    hero    subzero    zero   

trolley car    inke    crinkling    paper    ink-pot    pois    highlighter    inkhorn    foregather    pinna