'angostura' originates from Spanish, specifically the word 'Angostura', where 'angostura' meant 'narrows; narrowness' (from 'angosto' ‘narrow’, < Latin 'angustus' ‘narrow’).

'angostura' changed from the Spanish place name 'Angostura' and eventually became the modern English word 'angostura'.

Initially, it referred to the Spanish place/name meaning ‘narrows’, but it came to denote the bark from the region and later the bitters flavored with that bark.