'Aquilo' originates from Latin, specifically the word 'Aquilo', where the exact Proto-Indo-European root is uncertain but is often connected to roots denoting sharpness or swiftness (attributes associated with wind).

'Aquilo' changed from its Classical Latin usage as the name of the north wind into Late and Medieval Latin as a poetic term; it was later borrowed into English literary and poetic usage as 'Aquilo' with little change in form.

Initially, it meant 'the Roman personification of the north wind', but over time it evolved into its current usage meaning 'a cold north wind' or a poetic reference to the north wind in English.