un

uncanny (adj.) of supernatural character or origin (Luka had an uncanny ability to know exactly what other people were thinking. She also had an uncanny ability to shoot fireballs from her hands.)

unctuous (adj.) smooth or greasy in texture, appearance, manner (The unctuous receptionist seemed untrustworthy, as if she was only being helpful because she thought we might give her a big tip.)

undulate (v.) to move in waves (As the storm began to brew, the placid ocean began to undulate to an increasing degree.)