'anti-gnostical' originates from Greek and Late Latin elements: the prefix 'anti-' originates from Greek 'anti' meaning 'against', and 'gnostical' derives from Late Latin 'gnosticus', from Greek 'gnōstikos' meaning 'pertaining to knowledge'.

'gnōstikos' (Greek) gave Latin 'gnosticus', which passed into English as 'gnostic' and the adjective 'gnostical'; English formed compounds with the prefix 'anti-' (from Greek 'anti-') to create 'anti-gnostical'.

Initially the components referred generally to 'against knowledge' (anti- + gnōsis); over time the compound came to be used specifically to mean 'opposed to the religious/philosophical movement called Gnosticism'.