must-read

The compound "must-read" is a modern English formation, a product of functional shift and compounding in the 20th century. It combines the modal verb "must," which evolved from an Old English term denoting permission or ability into a word expressing compulsion or strong advisability, with the verb "read," descended from an Old English word with broader meanings of advising and interpreting. The logic of the compound is transparently literal: something one "must read." This construction follows a productive pattern in English for creating adjectival or nominal compounds (e.g., must-have, must-see) that succinctly label items deemed indispensable within a specific context, transforming a verbal phrase into a definitive descriptor or category.

Structure: must (obligation) + read (action of reading) - must: From Old English mōste, past tense of mōtan ("to be allowed, to be able to"). In modern English, it functions as a modal verb expressing necessity or strong recommendation. Its role here is adjectival, conveying a sense of strong obligation or high recommendation. - read: From Old English rǣdan ("to advise, interpret, read"), of Germanic origin. In this compound, it functions as the verbal element, specifying the action being recommended.