The compound adjective 'working-age' is a modern formation built from two deeply rooted English words. 'Working' originates from the Old English verb for labor and activity, its participial form commonly used to create adjectives describing a state or purpose. 'Age' traces back to Latin terms for lifetime and generation. Combined in the 20th century, the term logically and literally describes the specific 'age' span associated with the capacity and expectation for 'working', reflecting societal and economic classifications of the adult population.

Structure: working (to work) + age (period of life) - working: From Old English weorcian (to work, operate). A present participle form of the verb 'work', functioning as an adjective meaning 'engaged in work' or 'related to work'. - age: From Old French aage, eage, ultimately from Latin aetāticum (age, period of life). A noun root denoting a period or stage of life.