'counter-chorus' is a compound of 'counter' and 'chorus'. 'counter' originates from Latin via Old French, specifically the word 'contra' (Old French 'contre'), where 'contra' meant 'against'. 'chorus' originates from Greek, specifically the word 'khoros' (via Latin 'chorus'), where 'khoros' meant 'dance' or 'choral group'.

'counter' entered English via Old French 'contre' from Latin 'contra', and 'chorus' entered English from Latin 'chorus', from Greek 'khoros'. The compound 'counter-chorus' developed in modern English as a descriptive term for a chorus that counters or answers the main chorus.

Initially the components meant 'against' (for 'counter') and 'dance/choral group' (for 'chorus'), but together they evolved to mean 'a chorus that counters or responds to the main chorus' in musical contexts.