cinder-block

The compound "cinder-block" is a modern construction term that logically combines two ancient words to describe a specific building material. "Cinder" originates from the Old English sinder, referring to the residual slag or ash from a fire, which historically was used as a lightweight aggregate. "Block" descends from Middle Dutch blok, meaning a log or solid mass, a term that entered English to denote any sturdy, regularly shaped piece. The compound term emerged in the 20th century to specify a type of concrete masonry unit where cinders replace heavier aggregates like gravel, creating a lighter, more economical block. Thus, the name transparently denotes a solid, rectangular block made from cinder-based concrete.

Structure: cinder (noun) + block (noun) - cinder: From Old English sinder, meaning "slag, dross". The functional role is that of a material component. - block: From Middle English blok, meaning "solid piece". The functional role is that of the object's form and function.