A pattern imposed on complex reality or experience to assist in explaining it, mediate perception, or guide response.
American Heritage Medicine
A mental image produced in response to a stimulus, that becomes a framework or basis for analyzing or responding to other related stimuli.
Webster's New World
An outline or image universally applicable to a general conception, under which it is likely to be presented to the mind.
(databases) A formal description of the structure of a database: the names of the tables, the names of the columns of each table, and the type and other attributes of each column. (similarly for the descriptive information of other data description structures, such as the ones of XML files.)