Definition
who attempts (especially in vain) to appeal to young people by imitating them
How People Actually Use It
The state of being on the same wave length as members of a younger generation. To be cool, clued-up and enlightened as a result of ones knowledge and/or pursuit of the interests, passtimes and trends commonly associated with people younger than oneself. A characteristic commonly displayed by minor television personalities, celebrities and people involved in entertainment media, trend spotting, marketing and advertising.
"I better get myself snowboarding if I want to be down with kids. I almost broke my neck the other day learning how to skateboard but hey I'm down with the kids! British TV personality Alex Kramer is down with the kids! High five!"
Source: Urban Dictionary