The compound adjective 'then-current' is a modern analytical formation, combining two native English temporal words to create a specific historical reference. 'Then', an ancient adverb of time from Proto-Germanic, establishes the past frame. 'Current', from the Latin verb for running, evolved through French to mean "presently in flow or operation." When fused, the literal "at-that-time-now-existing" logic creates a precise term for describing what was considered contemporary or valid within a defined past context, effectively capturing a snapshot of past presentness. This construction highlights the flexibility of English in combining transparent elements to express nuanced temporal relationships.

Structure: then (at that time) + current (existing now) - then: From Old English þonne, þænne (then, at that time). An adverb functioning as a temporal modifier in this compound. - current: From Latin currere (to run), via Old French corant (running, flowing). An adjective meaning "belonging to the present time; now in progress."