Dog/dɔːɡ/ Definition 1 of 6Pro Tip 1/3Common Pet Dogs are popular pets worldwide, often considered family members. Children love playing with their pet dog. Pro Tip 2/3Loyalty Emblem Dogs symbolize loyalty and are known for being devoted and reliable. A dog is often called 'man's best friend' due to its loyalty. Pro Tip 3/3Helpful Service Dogs can be trained as service animals for various forms of assistance. Guide dogs help visually impaired people navigate.