The Spanish word 'oxalato' (oxalate) comes from Ancient Greek 'ὀξαλίς' (oxalis), which meant 'sorrel plant', combined with the Spanish chemical suffix '-ato'. Sorrel is a plant known for its sour taste, which is due to its high content of oxalic acid. The chemical term 'oxalato' refers to salts and esters of oxalic acid, maintaining the connection to the original plant source of these compounds.

A related Spanish word is 'oxálico' (oxalic), as in 'ácido oxálico' (oxalic acid), which shares the same Greek root. This is the acid naturally found in sorrel plants that gave rise to the name.

English speakers might recognize the related word 'oxalis', which is the scientific name for a genus of plants including wood sorrels. The word 'oxalate' is also directly related, being the English equivalent of the Spanish 'oxalato'. These terms all trace back to the same Greek word for the sorrel plant.