'anti-pacifism' is formed from the prefix 'anti-' (from Greek 'antí' meaning 'against') + the noun 'pacifism' (from French 'pacifisme', ultimately from Latin 'pax' meaning 'peace' + the suffix '-ism' indicating a doctrine or system).

'pacifism' entered English in the late 19th century from French 'pacifisme', which derives from Latin 'pax'/'pac-'. The prefix 'anti-' has been used in English since Classical and Medieval borrowings (via Latin/Greek) to mean 'against' and was later combined with 'pacifism' to form 'anti-pacifism'.

Initially it simply denoted 'opposition to pacifism.' Over time, its use has come to cover a range from philosophical rejection of pacifist principles to practical support for military or coercive measures in specific situations.