The meaning quoted will be found in the Dictionary under the alternative form geas
I quote from Whitley Stokes' translation, Revue Celtique, January 1901, and succeeding numbers.
Bregia was the great plain lying eastwards of Tara between Boyne and Liffey
“The Destruction of Da Derga's Hostel.”
Pronounced “Koohoo´lin.”
See [p. 150].
See pp. 121-123 for an account of this deity.
It is noticeable that among the characters figuring in the Ultonian legendary cycle many names occur of which the word Cu (hound) forms a part. Thus we have Curoi, Cucorb, Beälcu, &c. The reference is no doubt to the Irish wolf-hound, a fine type of valour and beauty.
Now Lusk, a village on the coast a few miles north of Dublin.
Owing to the similarity of the name the supernatural country of Skatha, “the Shadowy,” was early identified with the islands of Skye, where the Cuchulain Peaks still bear witness to the legend.