‘睁大’ is a compound verb meaning ‘to widen (one’s eyes)’, typically in response to surprise, shock, curiosity, or intense focus. The first character 睁 (zhēng) means ‘to open (the eyes)’, and the second character 大 (dà) means ‘big’ or ‘large’ — together they literally convey ‘open wide’. Unlike standalone verbs like 看 (to look), 睁大 always describes the physical action of widening the eyes, not general vision or observation.

This expression is commonly used in narrative or descriptive contexts — especially in storytelling, dialogue, or emotional scenes — to emphasize a character’s immediate, involuntary reaction. It often appears with objects like 眼睛 (eyes) or implicitly refers to them. While it can be used in both spoken and written Chinese, it carries a slightly literary or expressive tone and is rarely used in formal technical or administrative language.