one who flatters in the hope of gaining favors : sycophant
parasitesycophanttoadyleechsponge mean a usually obsequious flatterer or self-seeker. parasite applies to one who clings to a person of wealth, power, or influence or is useless to society. sycophant adds to this a strong suggestion of fawning, flattery, or adulation.
verb
to behave as a toady : engage in sycophancy
fawntoadytrucklecringecower mean to behave abjectly before a superior. fawn implies seeking favor by servile flattery or exaggerated attention. toady suggests the attempt to ingratiate oneself by an abjectly menial or subservient attitude.