'Chuī niú' literally means 'to blow a cow'—a vivid, humorous idiom that originated from the image of someone inflating a cow's hide like a balloon to make it appear larger than it is. Over time, it evolved into a common expression for exaggerating one’s abilities, achievements, or possessions in an obvious, often entertaining way. Unlike formal criticism of dishonesty, 'chuī niú' carries a light, colloquial tone and is frequently used among friends or in informal settings.

The phrase functions as a verb and can appear in various grammatical positions: as a predicate ('He loves to boast'), with aspect particles ('has been boasting'), or in imperative or descriptive constructions. It’s rarely used in formal writing or official speech, and its animal-based imagery makes it instantly recognizable and memorable for learners—especially given the cultural prominence of cattle in Chinese idioms and folklore.