Note 161b — THE GODODIN.
John Williams translation
It is still very common in Wales to call the cause or origin of any thing by the name of mam: thus, for instance, we say “mam y drwg” of the chief instigator of mischief. What we are to understand by the “mother of the lance” it is not very easy to determine; it might have been courage or the sense of wrong, or quarrel, or any other cause which excited the Britons to fight.