Noun
(electronics) an 80-mm (3-inch) CD (compact disc)
(music) a 3-inch CD single
CD3 (plural CD3s)
(immunology) an antigen, part of the T cell receptor (TCR) complex on mature T lymphocytes
Earth has a new temporarily captured object/possible mini-moon called 2020 CD3. Source: Internet
I did the whole exercise again using a different iPod but this time CD3 disappeared. Source: Internet