Prefixes are a group of letters that change the meaning of a word when they are added to the start. The prefix un- usually means 'not', so the new word means the opposite of the original. In this ...

Regarding Andy Kessler’s “Little to Like on the Prefix Menu” (Inside View, Aug. 28): Can we toss some non-prefix words, too? The ever-irritating “existential” and “performative,” for example—words so ...