OBSERVATION.The words enroll, unroll, miscall, befall, befell, bethrall, reinstall, disinthrall, fulfill, and twibill, are very commonly written with one l, and made exceptions to this rule; but those authors are in the right who retain the double letter.

"Twibill; an instrument with two bills, or with a point and a blade; a pickaxe, a mattock, a halberd, a battleaxe.