Green’s Dictionary of Slang

mosque n.

(UK Und.) a church.

[UK]G. Parker Life’s Painter 141: I must go to mosque tomorrow, where I am to nab a couple of neds from the humane society.
[UK]‘The Christening of Little Joey’ in Corinthian in Spedding & Watt (eds) Bawdy Songbooks (2011) IV 45: [as 1789].