The Spanish verb 'subastar' (to auction) comes from the Latin word 'subhastare', which literally meant 'to sell under the spear'. This Latin word was formed by combining 'sub-' (under) and 'hasta' (spear). This fascinating etymology reflects the ancient Roman practice of conducting public auctions: a spear (hasta) was traditionally planted in the ground to mark the location of public auctions, and sales were conducted 'under the spear'. The Spanish verb was formed by adapting the Latin word and adding the standard Spanish verb ending '-ar'.

While 'subastar' doesn't have many common Spanish relatives that would be immediately recognizable to beginners, it's worth noting that the 'sub-' prefix appears in many Spanish words like 'submarino' (submarine), 'subterráneo' (underground), and 'subrayar' (to underline), all carrying the meaning of 'under' or 'below'.

English speakers might recognize the 'sub-' prefix from many English words that share the same Latin origin, such as 'submarine', 'subterranean', and 'subtract', all carrying the meaning of 'under' or 'below'. While the 'hasta' (spear) part isn't commonly seen in English, it appears in the rare word 'hastated', meaning 'spear-shaped' in botanical descriptions.