I saw a Will Smith interview in which he talked about "his" word "jiggy" (as in "getting jiggy with it") making it into some dictionary or other and explained that it meant "Super, nuclear cool."

The Urban Dictionary corroborates this; however, how come in my dictionary "jiggy" is said to have a different meaning and predate Will Smith by over half a century?

jiggy

adj

1. uninhibited, especially in a sexual manner : the script required her to get jiggy with Leonardo. 2 trembling or nervous, especially as the result of drug withdrawal.

ORIGIN 1930s: from jig + -y.

I guess if ordinary mortals misunderstand and misuse a word they're corrected; but when someone famous does it, their mistake is immortalized in the dictionary.