header

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/ˈhɛdə/ English

Definitions

The upper portion of a page (or other) layout.“If you reduce the header of this document, the body will fit onto a single page.”
Text, or other visual information, used to mark off a quantity of text, often titling or summarizing it.“Your header is too long; "Local Cannibals" will suffice.”
Text, or other visual information, that goes at the top of a column of information in a table.“That column should have the header "payment status".”
A font, text style, or typesetting used for any of the above.“Parts of speech belong in a level-three header. Level-two headers are reserved for the name of the language.”

A file, usually in the form of source code, that is automatically included in another source file by the compiler.
A file that contains declarations but no implementations.