The word "大吹大擂" is formed by combining two parallel verb phrases, each prefixed with the intensifier "大" (meaning "big" or "loudly"): "大吹" (loudly blowing) and "大擂" (loudly drumming), where "吹" means to blow or boast and "擂" means to beat or drum. This structure creates a four-character idiom that literally depicts vigorous blowing and drumming, and through this juxtaposition, it conveys the figurative meaning of exaggerated boasting or showy promotion.