To determine or clearly exhibit the boundaries of; to mark the limits of; as, to define the extent of a kingdom or country.

To determine with precision; to mark out with distinctness; to ascertain or exhibit clearly; as, the defining power of an optical instrument.

To determine; to decide.

determine the essential quality of

determine the nature of; "What defines a good wine?"

delineate the form or outline of; "The tree was clearly defined by the light"; "The camera could define the smallest object"