Oh, wait...
neologism n.
a new word, usage, or expression;
a meaningless word coined by a psychotic
From French néologisme, from Greek neo- (new) + logos (word)
Usage:
As a young child, my daughter was a budding neologism fan. Among her gems was "clock o' morning", the hour at which one was supposed to wake up and not a minute before. I really wish this had caught on.