CB - What is a CB in football?

CB has 2 meanings. The most common is "Cornerback." See examples of how people use the terms.
In football, a CB is a cornerback, which is a defensive back (DB) that typically guards a wide receiver. The CB's primary job is to defend receivers, which are typically wide receivers (WR), tight ends (TE), and running backs (RBs).

2023 Fantasy Football WR/CB Match-Up Report Week 14: You Want to be Starting Courtland Sutton

Buffalo Bills sign DT Linval Joseph, place CB Kaiir Elam on injured reserve

Bengals take CB DJ Turner in second round of NFL draft - Sent-trib

Commanders maintain depth, protect comp picks by re-signing CB Danny Johnson - Hogs Haven

Next Gen Stats' top 10 coverage players of 2021: Cowboys CB on the board but it's not Trevon Diggs

2023 NFL Draft: Cornerback Cameron Mitchell, Northwestern, No. 142

Texas Newcomers Report: Longhorns CB Malik Muhammad is already living up to recruiting hype - Burnt Orange Nation

Freshman CB Woodard contributing early at Montana State – Skyline Sports

Giants select Maryland CB Deonte Banks in 1st round of NFL draft