This is an irregular feature - both in frequency and oddness - dedicated to a word I came across that I have never previously used.
tergiversation (tuhr-jiv-uhr-SAY-shun) n. The act of being evasive or of being purposefully ambiguous; being an apostate or renegade; abandoning a party, cause, or set of beliefs.
The verb form is tergiversate. No jokes about sending the word and its definitions along to Senator Joe Lieberman, please.
Tergiversation is derived from the Latin tergiversatus, meaning "to turn one's back" or "to shift."