Translation according to P. W. Joyce:
Larraga in Galway, and Larragan in Galway and Queen's Co.; Learga and Leargan a hill side. See vol. i. p. 403 [reproduced below].
The word learg [larg] signifies the side or slope of a hill; it is used in local names but not so often as leargaidh [largy], a derivative from it, with the same meaning. Largy, the most usual modernised form, is found only in the northern half of Ireland, and is almost confined to Ulster; it gives names to many townlands, both by itself and in combination. Largysillagh and Largynagreana are the names of two places near Killybegs in Donegal, the former signifying the hill-side of the sallows, and the latter, sunny hill-slope, from its southern aspect. The diminutive Largan, meaning still the same thing, is also of very common occurrence as a townland name, both singly and compounded with other words; Larganreagh in Donegal, grey hill-side.