From the Word of the Day feed in the right-hand column:
rubicund \ROO-bih-kund\, adjective:
Inclining to redness; ruddy; red.
Now, that's a word I cannot recall ever hearing used or even seeing in print. For example, I've never seen/heard this:
"My goodness, for some unknown reason, your posterior has become rebicund."
It's always been:
"Wow, sumpthin's got the red ass up on you!"