extrusion
(ɛkˈstruːʒən)
Also 6 extrution.
[f. as if ad. L. *extrūsiōn-em, n. of action f. extrūdĕre: see extrude.]
The action of extruding or thrusting out; the fact of being extruded.
1. In physical sense: a. The action of pushing out; expulsion by mechanical force. b. Protrusion from within an envelope; the putting forth (e.g. of a bud or branch, an eruption, etc.).
| 1638 W. R[awley] tr. Bacon's Life & Death 84 In all Alimentation, or Nourishment, there is a two-fold Action; Extrusion, and Attraction. 1684 T. Burnet Th. Earth i. 30 A violent depression of some parts of the earth, and an extrusion and elevation of others. 1839 Murchison Silur. Syst. i. xxxii. 436 This extrusion had been brought about by a succession of small upcasts. 1875 H. C. Wood Therap. (1879) 66 The extrusion of white blood-cells in the frog's mesentery. |
c. The pressing of metals, plastics, etc., into the required shape by extruding them through dies; also, the article so extruded (see extrude v. 1 d). Also attrib., esp. in extrusion press.
| 1921 Chem. Abstr. 3967 Details as to the app. used and the method of extrusion are given. In complete extrusions the rod produced was sound from end to end. 1937 Archit. Rev. LXXXI. 267/3 Aluminium alloy extrusions are used for casement sections, door frames, etc. 1940 New Statesman 16 Mar. 360/1 Extrusion of metal is the same, in principle, as squirting tooth-paste or spaghetti, or, better still, macaroni. Ibid., An extrusion press can make bars with curved cross-sections and bars containing longitudinal holes. 1962 M. G. Say Newnes Conc. Encycl. Electr. Engin. 104/1 The sheath is applied [to an electric cable] through a point and die by means of a ram or continuous extrusion lead-sheathing press. 1964 M. Gowing Britain & Atomic Energy 1939–1945 xii. 338 New premises..must be provided for the extrusion work on the rods. |
2. Expulsion by violent or rigorous measures from an abode, place, position of privilege, etc.
| 1540 Wyatt Let. to Cromwell Wks. 1816 II. 394 The treaties shall be followed to the extrusion from all their dominions. 1593 Tell-Trothe's N.Y. Gift 37 An vnkind extrution..of her out of dores. 1650 R. Hollingworth Exerc. conc. Usurped Powers 11 Meer forcible extrusion deprives not any lawfull Magistrate of his right. 1736 S. Sleech in Lett. Lit. Men (Camden) 365 An unjust..Extrusion from his College. 1780 Johnson L.P., Congreve Wks. III. 163 Upon the extrusion of the Whigs, some intercession was used lest Congreve should be displaced. 1875 Merivale Gen. Hist. Rome lxxix. (1877) 675 The extrusion of the people from the interior of the city. 1885 Manch. Exam. 10 Mar. 5/2 The extrusion of the hereditary principle. |