打 (dǎ): While its primary meaning is “to hit” or “to strike,” in many phrases like this one, it functions as a general action verb, similar to “to do” or “to engage in.” Here, it signifies the action of dozing.
瞌 (kē): This character specifically means “drowsy” or “sleepy.” It is almost never used on its own and exists primarily to form this word.
睡 (shuì): This is the standard character for “to sleep.”
The characters combine logically: “打 (dǎ)” means to perform the action of “瞌睡 (kēshuì),” which itself means “drowsy sleep.” So, the literal translation is “to do a drowsy sleep,” accurately capturing the idea of unintentionally dozing off.
In Chinese culture, “打瞌睡” is a universally understood phenomenon, but its perception is highly context-dependent.
In Formal Settings (School/Work): Dozing off during class or a business meeting is seen as a sign of disrespect, boredom, or laziness. A teacher might gently admonish a student, saying “别打瞌睡了！” (bié dǎ kēshuì le! - “Stop dozing off!”). It implies a lack of engagement and can cause someone to lose face.
In Informal Settings: Among friends or family, or during a long commute, it's a neutral and relatable experience. Complaining “我昨天没睡够，今天一直打瞌睡” (Wǒ zuótiān méi shuì gòu, jīntiān yìzhí dǎ kēshuì - “I didn't get enough sleep yesterday, I keep dozing off today”) is a common way to express tiredness.
Comparison to “Power Nap”: It's crucial not to confuse `打瞌睡` with a “power nap.” A power nap is an intentional, strategic act of resting to improve productivity. `打瞌睡`, however, is almost always unintentional and involuntary. It's what happens when you're *trying* to stay awake but can't. The Chinese equivalent for a planned nap would be `小睡 (xiǎoshuì)` or `午睡 (wǔshuì)`.