'tuna' originates from Spanish, specifically the word 'atún', which came from Arabic 'tūn', derived from Latin 'thunnus', and ultimately from Ancient Greek 'θύννος' (thúnnos), meaning 'tunny fish'.

'atún' transformed into the English word 'tuna' through Spanish influence.

Initially, it referred to the fish itself, and this meaning has largely remained the same in modern usage.