Merriam-Webster's Collegiate® Dictionary, 11th Edition
HEEL
I. noun see: hock Date: before 12th century
1. the back of the human foot below the ankle and behind the arch, the part of the hind limb of other vertebrates that is homologous with the human heel, an anatomical structure suggestive of the human heel, one of the crusty ends of a loaf of bread,
4. the part (as of a shoe) that covers the human heel, a solid attachment of a shoe or boot forming the back of the sole under the heel of the foot, a rear, low, or bottom part: as, the after end of a ship's keel or the lower end of a mast, the base of a tuber or cutting of a plant used for propagation, the base of a ladder, a contemptible person, heelless adjective
II. verb
Date: 1605
transitive verb
1. to furnish with a heel, to supply especially with money,
2. to exert pressure on, propel, or strike with the heel , to urge (as a lagging animal) by following closely or by nipping at the heels , intransitive verb to move along at someone's heels,
III. verb
Etymology: alteration of Middle English heelden, from Old English hieldan; akin to Old High German hald inclined, Lithuanian šalis side, region
Date: 1575
intransitive verb to lean to one side ; tip , transitive verb to cause (a boat) to heel,
IV. noun
Date: 1760
a tilt (as of a boat) to one side