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).

Panthers CB Donte Jackson emerges from 'dark hole' following torn Achilles, eager to prove himself

Ohio State trending for five-star CB, makes top schools for pair of four-star LBs - Land-Grant Holy Land

Top 10 2022 NFL Draft Cornerbacks From Ryan McCrystal

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

Football/Soccer: RHS Junior Boys Premier-Roles of Positions (Technical: Position specific, Academy Sessions)

Former NFL CB D.J. Hayden among 6 dead in car accident

Ex-UNC football star Dre Bly out as Tar Heels' CB coach - ESPN

Badgers CB enters the transfer portal - Bucky's 5th Quarter

Notre Dame CB Cam Hart Focused on Interceptions Over NFL Decision

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

Maryland CB Tarheeb Still: Terps 'Can Handle Whatever Is Thrown Our Way' - PressBox