'suspiro' originates from Latin, specifically the verb 'suspirare', where 'sub-' (or 'sus-') meant 'under/strongly' and 'spirare' meant 'to breathe'.

'suspiro' changed from Latin 'suspirare' through Vulgar Latin and Old Spanish forms (e.g. Old Spanish 'suspirar') and eventually became the modern Spanish noun and verb forms 'suspiro' and 'suspirar'.

Initially it referred to the act of breathing strongly or deeply; over time the sense narrowed to the emotional, audible exhalation now expressed by 'suspiro' (a sigh).