Etymology tree Proto-Indo-European *déḱm̥ Proto-Italic *dekəm Latin dec(em) Latin -nus Latin dēnus Proto-Indo-European *-yósder. Proto-Italic *-āzijos Latin -ārius Latin dēnārius Vulgar Latin *dīnārius Old Spanish dinero Spanish dinerobor. English dinero Borrowed from Spanish dinero (“money”). Doublet of denar, denarius, denier, dinar, diner, and dinheiro.