One who makes a show of liking another person with profuse or excessive displays of camaraderie, such as vigorous hand clasping, back-slapping, hearty words of greeting, etc.
A person who behaves in a servile manner, such as a sycophantic employee or a fawning lover.
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.