LOUGH Meaning of LOUGH in English [lough] n [ME, of Celt origin; akin to OIr loch lake; akin to L lacus lake--more at lake] (14c) 1 chiefly Irish: lake 2. chiefly Irish: a bay or inlet of the sea Merriam-Webster English vocab. Английский словарь Merriam Webster. 2012