The word is derived from Lithuanian word Lavonas, which means "dead-man". It is smart guy with decent salary, but walking around with dirty t-shirts and sweatshirts all the time and doesn't seem to care about it. It may apply to jeans, shoes, haircut, etc. as well.
Man 1: Hey, have you seen Michael?!
Man 2: Yeah, he doesn't seem like lavon anymore with his new sweat-shirt.
Man 1: No worries, after a week or so he will look like lavon again.
A La'Von is a person who is kind of funny, but sort of weird. He usually stays at home and likes to play video games a lot. He is very fun to be around on the outside, but he faces many difficulties in life on the inside. He likes to joke around, but tends to do it a little too often. He is a loyal friend who likes to talk and is usually friendly to the new people he meets. He's usually a boss at school and tends to make fun of people in a good way. Finding a La'von is very rare, but they are definitely worth keeping.