A Scottish word, variously given in old Scottish as farle, farthel or ferl. Used to describe a fourth part of a round, flat cake, either of oatmeal or flour. The word is still in use in parts of Scotland and the north of Ireland, but is loosely used to indicate a whole round or scone as well as a separated part. The term was at one time confined to a description of an oaten farl, which might be one-quarter or more generally one third or a round.
From The Baker’s ABC by John Kirkland, formerly Head Teacher of National School of Baking, published 1927 by Gresham