1any of the more or less distinct parts into which something is or may be divided or from which it is made up: I unscrewed every section of copper pipe, from the roof tank to the hot-water cylinder a relatively distinct part of a book, newspaper, statute, or other document: the New York Times business section this last section of the questionnaire relates solely to training North American a measure of land, equal to one square mile.
chiefly North American a particular district of a town: a residential section of the capital
2a distinct group within a larger body of people or things:the non-parliamentary section of the party a group of players of a family of instruments within an orchestra:the brass section [in names] a specified military unit:a GHQ Signals Section a subdivision of an army platoon. Biology a secondary taxonomic category, especially a subgenus.
3 [mass noun] the cutting of a solid by or along a plane. the shape resulting from cutting a solid along a plane: nails of round section [count noun] a representation of the internal structure of something as if it has been cut through vertically or horizontally: a section of face, showing the position of the organs of speech [count noun] Surgery a separation by cutting. [count noun] Biology a thin slice of plant or animal tissue prepared for microscopic examination. 1divide into sections:she began to section the grapefruit
(section something off
) separate an area from a larger one:parts of the curved balcony had been sectioned off with wrought-iron grilles
Biology cut (animal or plant tissue) into thin slices for microscopic examination: the specimens were embedded and serially sectioned Surgery divide by cutting:it is common veterinary practice to section the nerves to the hoof of a limping horse
2British commit (someone) compulsorily to a psychiatric hospital in accordance with a section of a mental health act:should she be sectioned and forced back into hospital?