1. a small floating device attached to a fishing line to indicate when a fish is biting
2. something that bobs up and down in water

Examples

• The bobber suddenly disappeared under the water, signaling a fish had taken the bait.
• He attached a red and white bobber to his fishing line.
• Watch the bobber carefully for any movement.
• The cork bobber floated gently on the lake’s surface.
• When the bobber goes under, set the hook quickly.
• She used a bright yellow bobber so she could see it easily.