September is Etymology Month (8)

ЦЕРКОВЬ [cérkov'] 'church'. In origin the acc. case (цьркъвь) of 11th-century цьркы, probably from late Gk. kurikón 'God's house', from earlier (4th century AD) adj. kuriakón 'the Lord's', which was substantivised as 'communion' (from kuriakón deipnon, id., lit. 'the Lord's meal') then 'church' (ellipsis for to (doma) kuriakón 'House of the Lord'). Ultimately from Gk. kúrios 'lord' (Kúrios 'Christ'), with k- changing to ц- (for k- to ч- by first palatalisation of velars, cf. Bulg. черква, alongside църква 'church'). Possibly via. Goth. *kirikô, id. or OHG kiricha, id. (cf. Ger. Kirche, id.). Cf. also cognate куролесить 'to play tricks'.