'anti-Puritan' originates from the combining of the prefix 'anti-' (from Greek 'anti-' meaning 'against') and the English word 'Puritan' (from Late Latin/French origins related to 'purity').

'Puritan' entered English in the late 16th century from ecclesiastical/vernacular forms influenced by Late Latin 'puritanus' and Medieval/French usage; the compound 'anti-Puritan' is an English formation using the productive prefix 'anti-' plus 'Puritan' to denote opposition.

Initially the parts meant 'against' + 'Puritan'; over time the compound has been used to describe attitudes, critiques, or people opposed to Puritans or Puritanism and retains that core sense but can apply more broadly to opposition to strict moralism.