*11 A word that means its own opposite is a contronym, though the term “Janus word”—you remember two-faced Janus, looking ahead and behind at the same time, yes?—is also applied, and it packs a thrill. “Sanction” (to allow and to penalize) and “cleave” (to hold fast and to cut up) are classic Janus words. And though context will easily indicate for these two which meaning is being used, I wouldn’t say the same re “nonplussed,” so let’s hold on to just the one meaning, OK?
