1. a dog trained or kept to protect a person, property, or place from intruders or danger
Usage: typically used in singular or plural form; common in security and property protection contexts

Examples

• The family's guard dog barked loudly whenever strangers approached the house.
• German Shepherds are popular choices for guard dogs because of their intelligence and loyalty.
• The warehouse hired a guard dog to patrol the grounds at night.
• A well-trained guard dog can detect threats before they become dangerous.
• The guard dog alerted the owner to the intruder in the backyard.
• Many businesses use guard dogs as part of their security system.