'antineutrino' originates from the combining form 'anti-' (from Greek 'anti-', meaning 'against' or 'opposite') and 'neutrino' (Italian, a diminutive of 'neutro' meaning 'neutral').

'antineutrino' was formed in English by combining the prefix 'anti-' with the Italian-derived scientific noun 'neutrino' (coined in the early 20th century), producing the modern English scientific term 'antineutrino'.

Initially, it denoted the particle considered opposite to a neutrino; this core meaning—'the antiparticle of a neutrino'—has remained stable in modern usage.