A location in southwest Scotland, probably in the country of Galloway.
After Sir Galleron and Sir Gawain fought each other to a draw, Gawain, in admiration, gave all the lands “from Laner to Layre” to Galleron.
The lands had originally belonged to Galleron and were annexed by Arthur and given to Gawain.
See also
Laner | The Legend of King Arthur
Source
The Awntyrs off Arthure at the Terne Wathelyn | Late 14th century