The Spanish word 'relave' comes from combining two Latin elements: the prefix 're-' meaning 'again' and the verb 'lavare' meaning 'to wash'. These combined to form the Spanish verb 'relavar' (to wash again), and with the addition of the noun-forming suffix '-e', created 'relave'. While literally meaning 'rewashing', it has come to specifically refer to the 'tailings' or waste material left over after ore processing in mining, which historically involved multiple washing processes.

Several common Spanish words share this etymology through the Latin 'lavare'. The most basic is 'lavar' (to wash), which is a direct descendant of Latin 'lavare'. You might also recognize 'lavadora' (washing machine), 'lavaplatos' (dishwasher), and 'lavandería' (laundry). All these words connect to the basic concept of washing or cleaning.

English has several words that come from the same Latin root 'lavare'. The word 'lavatory' is perhaps the most direct descendant, originally referring to a washroom. 'Laundry' and 'lather' are also related, both connecting to the concept of washing. The prefix 're-' is very common in English and has the same Latin origin, meaning 'again' or 'back', as seen in words like 'return', 'repeat', and 'reverse'.