1. a dog, especially a pet dog (informal, often used as a generic name)
Usage: informal; often capitalized when used as a proper name for a specific dog

Examples

• My neighbor's fido barks every time someone walks past the house.
• Fido loves to play fetch in the park.
• We took fido to the veterinarian for his annual checkup.
• The children were excited to meet their new fido.
• Fido wagged his tail when his owner came home from work.