'Argentinian' originates from Spanish 'Argentina' (and Spanish adjective 'argentino'), which in turn comes from Latin 'argentum' meaning 'silver'.

'argentum' (Latin) gave rise to place names and adjectives in Romance languages; the name 'Argentina' (Spanish) was used for the region associated with the Río de la Plata and then adopted into English as 'Argentina', from which the adjective and demonym 'Argentinian' developed.

Initially associated with 'silver' through the Latin root, the term evolved to name the region and then the nation; it now primarily means 'of or from Argentina' or 'a person from Argentina'.