'vasorelaxation' originates from modern scientific English, formed by the combining form 'vaso-' (from Latin 'vas', meaning 'vessel') and the noun 'relaxation' (from Latin 'relaxare', meaning 'to loosen').

'vasorelaxation' was coined in 20th-century medical usage by combining the prefix 'vaso-' (derived from Latin/Medieval Latin 'vas') with the English word 'relaxation' (from Latin 'relaxare'); the components passed from Latin into Medieval Latin and then into modern English medical terminology.

The components originally meant 'vessel' and 'to loosen'; over time the compound came to denote specifically 'the loosening/relaxation of blood vessels'.