'antiproton' originates from Greek and modern scientific coinage, specifically the prefix 'anti-' (from Greek 'ἀντί') meaning 'against' or 'opposite' and 'proton' (from Greek 'πρῶτον' prōtos) meaning 'first'.

'antiproton' changed from the combination of the prefix 'anti-' + the word 'proton' after the proton had been named in early 20th-century physics; the term 'antiproton' entered scientific usage in the mid-20th century following the particle's theoretical prediction and experimental discovery.

Initially, it referred to the particle opposite in charge to the proton; over time the term has remained stable and continues to denote the proton's antiparticle.