A lapdog is a small dog that people often keep as pets and like to cuddle with. These dogs are usually very friendly and affectionate.
You might hear someone call their friend's pet a "lapdog" if they're always sitting on their lap, whether it's on the couch or in bed. This can be a bit negative, though - sometimes people use the term "lapdog" to imply that someone is too eager to please others or doesn't think for themselves. But when used more lightly, it just means the dog loves being close to its owner and will happily snuggle up on their lap whenever possible.
A small toy dog, kept as household pet, whose light weight and companionable temperament make it both suited and disposed to spend time resting in the comfort of its master's lap; a dog bred to behave in this manner.
