from main (n.) physical strength, force or power (from Old English mæᵹen, = Old Saxon megin, Old High German magan, megin, Old Norse magn, megn, megin, from root mag-) + -ful
Þe liflade of St. Juliana
From Two Old English Manuscripts of 1230 A.D.
With Renderings into Modern English by the Rev. O. Cockayne, and Edmund Brock
Edited by the Rev. Oswald Cockayne, 1872