dirt-cheap

the compound "dirt-cheap" is a vivid english colloquialism that emerged in the 19th century. its logic is one of hyperbolic comparison, equating the low cost of an item to the negligible value of common dirt or soil, which is ubiquitous and considered worthless. the word "dirt" itself derives from old norse "drit" meaning "excrement," but its sense broadened in middle english to mean "loose earth." "cheap" originates from the old english "ceap," meaning "bargain" or "trade," and evolved to signify low cost. thus, the term literally means "as inexpensive as dirt," leveraging a concrete, universally available substance to emphasize extreme affordability.

Structure: dirt (sense) + cheap (sense) dirt (old english, meaning "excrement, filth, earth") + cheap (old english, meaning "bargain, low price, of little value")