The Spanish verb 'asar' (to roast) comes from Latin 'assare' meaning 'to roast'. This Latin verb was derived from 'assus' meaning 'roasted' or 'dry', which developed from the reconstructed participle '*arsus' (burned) of the Latin verb 'ardeo' (to burn). The evolution shows how the general concept of burning narrowed to specifically refer to cooking by roasting.

A common related Spanish word is 'asado', which is both the past participle of 'asar' and a noun meaning 'roast' or 'barbecue'. You might hear this word frequently in Latin American cuisine, as in 'asado argentino' (Argentine barbecue). Another related term is 'asadura' meaning 'roasted meat' or 'entrails'.

While English 'roast' comes from a different root, we can find some English cognates from the Latin 'ardeo'. The English word 'ardent' (passionate, burning with intensity) comes from the same Latin root, as does 'arson' (the criminal act of burning property). The word 'ash' is also distantly related, all connecting back to the concept of burning.