Ischoolconnect.com has a big blog entry about new words in the English language.
It's an interesting list, but I don't think it represents truly new terms. For example, "knell" was used by Edgar Allen Poe in his poem "The Bells".
The very first word, abnegation, has its roots in a similar medieval word and Latin before that. However, this may be a word that is being used by young people more in recent years because it is the name of one of the "factions" in the young adults' series "Divergent".
I must read the blog again from that viewpoint.