jammer
nounUK /ˈdʒæm.ər/
US /ˈdʒæm.ɚ/
A jammer is a machine that stops signals like radio or phone signals from working.
The police used a jammer to block the thieves' phone signals.
OTHER MEANINGS
2. A person who plays in a music jam session.
The drummer is a talented jammer who plays with many bands.
3. A device used to jam enemy radar or communications in warfare.
The soldiers deployed a radar jammer to confuse the enemy.
4. In sports, a player who jams or blocks opponents, especially in roller derby.
She is a strong jammer who scores points for her team.