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).

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

10 things to know about Cowboys CB Trevon Diggs, including his own barbecue sauce

Notre Dame CB Cam Hart Focused on Interceptions Over NFL Decision

CB South turns Plymouth Whitemarsh mistakes into touchdowns – PA Prep Live

NFL Draft prospect Devon Witherspoon's football highlights wow fans

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

Falcons NFL Draft 2023: Atlanta selects CB Clark Phillips III with pick No. 113 - The Falcoholic

Big Ten CB Rankings 2023: Kalen King Crowned the top Cornerback in the Conference

Jets CB Sauce Gardner's Eye on First Pick of the Season vs. Chargers

Brice Pollock - Football - Mississippi State

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

Browns waive CB A.J. Green III after claiming Kahlef Hailassie off of waivers