Scrutiny is when you look at something really closely, like when you are checking a test for mistakes. Scrutiny can also be an intense look, like when your mother looks at you — trying to tell if you might be lying.
Scrutiny comes from the Latin scrutari, which means “to search,” but which originally meant, “to sort trash.” The most common usage of scrutiny is in the phrase “under scrutiny." When your work is under scrutiny, it’s like your teacher is looking for any trash that can be edited out. If your outfit is under scrutiny, your mom is checking to see if your skirt is long enough for school; she’s making sure you don’t look trashy.