long-extinct

The compound adjective 'long-extinct' is formed by combining the native English intensifier 'long', denoting an extensive period, with the Latinate adjective 'extinct', which signifies a state of having been quenched or terminated. The literal sense from Latin extinguere—'to put out, quench'—was applied metaphorically to lineages and species, implying their 'fire of life' has been doused. In this compound, 'long' amplifies the temporal distance, emphasizing that the extinction event occurred in the distant, often prehistoric, past. Thus, the term logically builds from the concept of 'extinguished for a great duration' to its specialized modern meaning describing species or phenomena that vanished ages ago.

Structure: long (duration) + extinct (state) - long: From Old English lang, long, of Germanic origin; related to Dutch lang and German lang. Functions as an adverb/adjective meaning 'for a great duration'. - extinct: From Latin extinctus, past participle of extinguere meaning 'to extinguish'. Functions as an adjective meaning 'no longer in existence'.