'counter-demonic' is a compound of the prefix 'counter-' and the adjective 'demonic'. 'Counter-' originates from Latin via Old French 'contre'/'contre-', ultimately from Latin 'contra' meaning 'against'. 'Demonic' originates from Greek 'daimon' (δαίμων) meaning 'spirit' via Late Latin 'daemonicus' meaning 'of a demon' and Middle English forms.

The element 'counter-' came into English from Old French 'contre' (from Latin 'contra') meaning 'against'. 'Demonic' derives from Greek 'daimon' through Late Latin 'daemonicus' and Middle English usage to mean 'pertaining to demons'; the modern compound 'counter-demonic' is a straightforward combination in Modern English to denote opposition to demonic forces.

Individually, 'counter-' meant 'against' and 'demonic' meant 'pertaining to demons' (or spirit-related). Together the compound initially and currently means 'opposed to demonic forces' and has also taken on figurative uses opposing perceived evil; the core sense has been preserved while expanding metaphorically.