kæs-tê-gayt • Hear it!
Part of Speech: Verb, transitive
Meaning: To severely reprimand or chastise.
Notes: This is a normal Latinate verb with the usual kinfolk. The noun is castigation and the adjective, castigative. Anything deserving of castigation is castigable; just be sure to drop the suffix -ate before adding -able—and add -able, not the more expectable -ible.
In Play: Today's Good Word is no longer used in the sense of physical punishment but rather to refer to an extreme chastisement: "I understand that Earl castigated his father for cutting him out of the will. I'm sure that will help change the old man's mind." Castigation, of course, always does more harm than good, so it is best avoided: "Instead of castigating me for everything I do wrong, why not give me a few bucks to do better?"
Word History: Today's punishing word comes from castigatus, the past participle of Latin castigare "to set right, correct, chastise, reprove", itself based on castus, "pure". The root of castus originally meant "cut". Castle originated in Latin castellus, from castrum "camp", something usually set up in a clearing created by cutting down trees. How the meaning "cut" shifted in castus to "pure, chaste" is rather mysterious ("having all flaws cut out?") but itself was borrowed directly from Latin for English caste. When the CA in Latin castellus changed to the French CHA we see today in chateau, castus followed the same rule to become chaste, which English also promptly borrowed, this time with the original sense. (Larry Brady, the Stargazer of the Alpha Agora, sends us lexical gems of unquestionable purity that we always enjoy.)