'antipacifist' originates from the prefix 'anti-' (from Greek 'anti' meaning 'against') combined with 'pacifist,' which comes from French 'pacifiste' and ultimately Latin 'pacificus' (from Latin 'pax/ pac-' meaning 'peace').

'antipacifist' developed in Modern English as a compound of 'anti-' + 'pacifist'; it was modeled on similar compounds (for example 'anti-militarist' or the phrase 'anti-pacifist') and came into use as a single lexical item.

Initially it meant simply 'against pacifists' or 'opposed to pacifism'; over time the term retained that core sense and has been used to describe people, rhetoric, or policies that reject pacifist principles or support forceful responses.