'inquietar' originates from Latin, specifically the word 'inquietare', where 'in-' meant 'not' and 'quietare' meant 'to make quiet / to calm.'

'inquietar' changed from the Latin word 'inquietare' into Old Spanish forms (recorded similarly) and eventually became the modern Spanish word 'inquietar'.

Initially, it meant 'to disturb or remove rest,' but over time it evolved into its current primary senses of 'to worry' or 'to unsettle.'