The word 'spunky' has a fiery and spirited history. Its core, 'spunk', entered English from Scots and Irish English, where it originally meant a spark or a fragment of burning material, itself likely derived from Latin 'spongia' (sponge) via a metaphorical link to tinder. By the 18th century, 'spunk' evolved metaphorically from a literal spark to the figurative 'spark of life' or 'inner fire', denoting courage and spirit. Adding the native English adjectival suffix '-y' (meaning 'full of') to this root created 'spunky', an adjective describing someone brimming with that lively, courageous spark.

Structure: spunk (spirit, courage) + y (adjective-forming suffix) - spunk: Likely of Scottish and Irish origin, originally meaning 'spark', later developing the sense of 'spirit, mettle'. It functions as the core noun root. - y: A native English suffix (from Old English '-ig', Proto-Germanic '-īgaz') used to form adjectives meaning 'characterized by; full of'.