A person who attempts to gain advantage by flattering influential people or behaving in a servile manner. A tale-bearer or informer in general. A parasite; a mean flatterer; especially, a flatterer of princes and great men.
The American Heritage® Dictionary of the English Language, 5th Edition
sycophant /sĭk′ə-fənt, sī′kə-/ noun
The American Heritage® Dictionary of the English Language, 5th Edition