A nominalized adj., from Copt marēs (region in Upper Egypt, boardering on Nubia), lit. ‘(the wind blowing) from the marēs region’.
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▪ Corriente2008: (EgAr mirīsī :) (following Bishai1964) from Copt marēs ‘country of the south, southern region’1
(ma ‘country’ + rēs ‘south’ (cf. Eg ʕ-rs.j ‘southern province; Upper Egypt’ – ThLAeg) ▪ Dozy1881 thinks that also the ↗marīsaẗ type of beer takes its name from the marēs region. But cf. s.v. for other etymologies.