Heading p. pr. & vb. n. : of Head

Heading n. : The act or state of one who, or that which, heads; formation of a head.

Heading n. : That which stands at the head; title; as, the heading of a paper.

Heading n. : Material for the heads of casks, barrels, etc.

Heading n. : A gallery, drift, or adit in a mine; also, the end of a drift or gallery; the vein above a drift.

Heading n. : The extension of a line ruffling above the line of stitch.

Heading n. : That end of a stone or brick which is presented outward.

Example:
How do you remove different Heading levels of text in a word document while keeping the text?

Taxonomy
free encyclopedia, search, disambiguation pages, free dictionary, guideline, extruding, processes, newspaper article, vehicle, nose, locomotives, train, bibliographic control, Personal tools, Interaction, Toolbox, non-profit organization, headlines.

Defination from the web:
Heading (metalworking), a process which incorporates the extruding and upsetting processes. Headline, text at the top of a newspaper article ... Aircraft heading, the direction that the aircraft's nose is pointing. Double-heading, the use of two locomotives at the front of a train ...