What is the X in X-mas?
"practice of innovation in language," 1776, from French néologisme, from neo- (see neo-) + Greek logos "word" (see lecture (n.)). Meaning "new word or expression" is from 1803. Neological is attested from 1754.
neologism ne·ol·o·gism (nē-ŏl'ə-jĭz'əm)n. A meaningless word used by a psychotic.