To chastise someone used to mean to punish that person with a physical beating.
But these days, to chastise people is to punish them with words (so that you teach them the right thing to do).
(Here's Charles Elster: "When a teacher chastises a student today, it's with harsh words, not a hickory stick.")
Either "chass TIZE"
or "CHASS tize."
Part of speech:
(Like "eat," "try," and "want," all transitive verbs do something to an object.
You eat a banana, try a game, and want a new phone.
Likewise, you chastise someone.)
Other common forms: chastised, chastising, chastisement(s)
How to use it:
The tone of this word can be serious, but you can also use it lightheartedly.
You can simply chastise someone: "I had to throw out my gum, and she chastised me after class." But most often, you chastise someone for something bad, or for doing something bad: "she chastised them for their laziness," "he chastised her for flaking out on their plans again."
Often we'll use the passive voice: "he was chastised by his boss," "she's getting chastised by the media."
Most of the time we chastise people (or groups of people), but occasionally we chastise the things they did: "we chastised his rudeness," "they chastised our overspending."
examples: In the cold, dystopian world of The Giver, Jonas's parents chastise him for using language imprecisely; they "enjoy" him, they "take pride in his accomplishments," but they don't "love" him.
On the forum, he was roundly, and may I say justly, chastised for defending Kirk as the superior Enterprise captain.