Obsequious behavior towards someone important in order to gain advantage. His sycophancy towards the boss was evident in the way he constantly praised her decisions.
Servile flattery; the practice of excessively praising or flattering someone powerful in order to gain personal advantage. Her open sycophancy made everyone roll their eyes whenever the CEO entered the room.
An act or instance of such obsequious flattery. Inviting the senator to a luxurious weekend retreat was just another of the lobbyist’s sycophancies.