I derived(/bastardized, whatever) a word and another yesterday...
They used to be nespy, but now they are both cesty.
in existence; existent, extant: The word cesty has only recently become self-descriptive.
[Origin: 2006; from French, c'est]
not in existence; nonexistent, nonextant: Yesterday has become incredibly nespy, despite being quite cesty about 15 hours ago.
[Origin: 2006; from French, n'est pas]