'descanso' originates from Spanish, specifically the word 'descanso', where the prefix 'des-' (from Latin 'dis-') meant 'away, undo' and the root is related to Latin 'cansare'/'cans-'/Old Spanish 'cansar' meaning 'to tire'.

'descanso' changed from Late Latin/Vulgar Latin forms such as 'discansare' or 'descansare' (formed from dis- + cansare) into Old Spanish verbs like 'descansar' and the noun 'descanso', eventually becoming the modern Spanish 'descanso' and later entering English as a loanword in specific contexts.

Initially it meant 'a ceasing of tiredness; rest' in the sense of stopping weariness; this basic meaning remains in Spanish and general English use, while in regional English it has also acquired the specialized meaning of a roadside memorial.