Late Middle English. Probably from Middle French secresterie or its etymon post-classical Latin secrestaria, variant of sacristaria (frequently 1160–1537 in British sources; compare also sacristria; from sacristia + classical Latin -āria), perhaps influenced by vestry.
Definition of sextry in US English:
sextry
nounˈsɛkstri
historical
Sacristy.
Origin
Late Middle English. Probably from Middle French secresterie or its etymon post-classical Latin secrestaria, variant of sacristaria (frequently 1160–1537 in British sources; compare also sacristria; from sacristia + classical Latin -āria), perhaps influenced by vestry.