‘呼救’ is a compound verb meaning 'to cry for help' or 'to call out for assistance.' It combines two characters: 呼 (hū), meaning 'to shout' or 'to call,' and 救 (jiù), meaning 'to save' or 'to rescue.' Together, they convey the urgent act of vocalizing a plea for immediate aid — typically in emergencies such as accidents, medical crises, or dangerous situations. Unlike general expressions like 'help!' in English, 呼救 implies life-threatening urgency and often involves loud, repeated shouting to attract attention.

This word is commonly used in formal contexts like safety training, news reports, emergency protocols, and public service announcements. It’s rarely used in casual conversation unless describing a serious incident; people usually say '救命！' (jiù mìng!) for spontaneous cries. 呼救 can function as both a verb ('He began to 呼救') and a noun ('The victim's 呼救 was heard by neighbors'), though its verbal use is far more frequent.