They are very close. To lie: to intentionally give false information To belie: to tell lies about; to slander Examples: He lied about his age because he wanted to rent a car. He belied his youth because he wanted to rent a car. Confusing, right? Don't worry; belie is very rarely used. You can find it in Shakespeare, but I don't think I've EVER used "belie" in my life - and I'm 62! I think the only time I might use that word is if I'm trying to sound like I'm from the Middle Ages. My advice - know that it is a word, but it is a word you'll never need. ;-)

belie=to give a false impression, to hide the truth, to fail to fulfil, to hide or mask true feelings and thoughts. lie = to tell an untruth. a few example sentences https://www.merriam-webster.com/dictionary/belie