Definition of lobe

• n. - Any projection or division, especially one of a somewhat rounded form
• n. - A rounded projection or division of a leaf.
• n. - A membranous flap on the sides of the toes of certain birds, as the coot.
• n. - A round projecting part of an organ, as of the liver, lungs, brain, etc. See Illust. of Brain.
• n. - The projecting part of a cam wheel or of a non-circular gear wheel.