Real Dictionary

ear
countable noun: Your ears are the two parts of your body, one on each side of your head, with which you hear sounds.

ear in American English 1
the part of the body specialized for the perception of sound; organ of hearing: the human ear consists of the external ear, the middle ear (tympanum), and the inner ear (labyrinth), which also senses one's state of equilibrium
noun: the organ of hearing and equilibrium in vertebrates, in humans consisting of an external ear that gathers sound vibrations, a middle ear in which the vibrations resonate against the tympanic membrane, and a fluid-filled internal ear that maintains balance

ear in American English 2
the grain-bearing spike of a cereal plant, esp. of corn
to sprout ears; form ears
intransitive verb: to form or put forth ears
noun: the part of a cereal plant, as corn, wheat, etc., that contains the flowers and hence the fruit, grains, or kernels

ear in American English 3
transitive verb: to plow; cultivate

ear in British English 1
noun: the organ of hearing and balance in higher vertebrates and of balance only in fishes. In humans and other mammals it consists of three parts

ear in British English 2
noun: the part of a cereal plant, such as wheat or barley, that contains the seeds, grains, or kernels
verb: (of cereal plants) to develop such parts