'perfectly-preserved' originates from modern English compounding of the adverb 'perfectly' and the past participle adjective 'preserved'; 'perfectly' traces back to Latin 'perfectus' (through 'perfect') + the adverbial suffix '-ly', and 'preserved' to Old French 'preserver' from Latin 'praeservare' ('prae-' meaning 'before' + 'servare' meaning 'to keep').

'perfectly-preserved' developed from the open phrase 'perfectly preserved' in modern English, with hyphenation used especially in attributive position. The elements derive from Middle English 'parfit'/'parfite' (from Old French, from Latin 'perfectus') and Middle English 'preserven' (from Old French 'preserver', from Latin 'praeservare').

Initially, the compound simply described something preserved in a perfect manner; its modern use continues this sense, typically emphasizing absence of deterioration and intact details.