Translation according to P. W. Joyce:
Lurga, Lurgan, a shin or long hill, a long strip of land : see vol. i. p. 527 [reproduced below].
The shin. Irish lurga or lurgan. This word like the last, was often applied to a long low ridge, or to a long stripe of land. From the first form, some townlands, chiefly in the south, are called Lurraga. The second form was much used in the northern and western counties, in which there are about thirty places called Lurgan, and more than sixty others of whose name it forms a part.