'sumptuous' originates from Latin, specifically the word 'sumptuosus', where 'sumptus' (from 'sumere') meant 'expense' or 'that which is taken (by spending)'; 'made' originates from Old English 'macian', meaning 'to make', whose past forms gave modern 'made'.

'sumptuosus' changed into Old French (as roots seen in words like) 'sumptueux' and then into Middle English as 'sumptuous', eventually becoming the modern English 'sumptuous'; Old English 'macian' became Middle English 'maken' (with irregular past forms), yielding the modern verb 'make' and past participle 'made'.

Initially, the root related to 'expense' or 'costly expenditure' (hence implying costly display); over time this developed into the sense 'lavish, costly, richly ornamental' used in 'sumptuous' and compounds like 'sumptuously-made'. The meaning of 'made' has remained essentially 'constructed' or 'produced', so the compound now specifically means 'constructed in a lavish manner'.