A "blocker" refers to something or someone that prevents progress or forward movement. It creates obstacles and hinders the completion of a task or the achievement of a goal. Full definition
What you can do: Minimize your ad exposure by watching less TV and possibly installing ad blockers in your browser so you can avoid food ads. (cravethebenefits.com)
King said the results indicate that doctors should reconsider use of beta blockers for patients following angioplasty. (health.com)
The upcoming ad blocker in Chrome gives Google the ability to cripple the revenue of any online rival, instantly. (howtogeek.com)