To belie means to contradict. If you are 93 but look like you are 53, then your young looks belie your age.
We get belie from the Old English beleogan, which meant "to deceive by lying." It suggests characteristics or behavior that inadvertently or deliberately hide the truth. To remember it, just think "be lying." Snow White's decision to barge into the Seven Dwarfs' home without invitation belied her gentle nature.