boicotear

To boycott — to organize a refusal to buy, use, or participate in something as a form of protest: boicotear una marca, boicotear las elecciones. The word itself comes from Charles Boycott, a 19th-century Irish land agent ostracized by his tenants, whose name became a byword for the tactic.

• Los consumidores decidieron boicotear la marca por sus políticas laborales. — Consumers decided to boycott the brand over its labor practices.
• Varios países boicotearon los juegos por razones políticas. — Several countries boycotted the games for political reasons.
• Amenazaron con boicotear las elecciones si no se garantizaba la transparencia. — They threatened to boycott the elections if transparency wasn't guaranteed.

Boicotear specifically implies an organized, collective refusal to participate as protest — it's stronger than simply 'avoiding' or 'ignoring' something, which wouldn't need this word.