orientableadj.
/ˈɔːrɪəntəbl/, /ˈɒrɪəntəbl/, /ˌɔːrɪˈɛntəbl/, /ˌɒrɪˈɛntəbl/, U.S. /ˈɔriən(t)əb(ə)l/, /ˌɔriˈɛn(t)əb(ə)l/ 1. Capable of being oriented (in various senses).
ΘΚΠ
the world > space > direction > [adjective] > turning or able to face any direction
turnable1483
convertible1526
versable1623
various1629
versatile1658
tropic1677
orientable1912
1912 Times 30 Oct. 22/4 The orientable tail skid arrangement..provides an independent land rudder.
1935 A. P. Herbert What a Word! iii. 85 One of our great motor-manufacturers advertises ‘A very neat orientable anti-glare visor’.
1960 L. Picken Organization of Cells vii. 265 Cleveland's material suggests only that in hypermastigine flagellates the centrioles utilize all orientable material.
1982 Aviation Week & Space Technol. (Nexis) 29 Nov. 84 The ship system contains six firing tubes mounted on an orientable turret.
2003 Millimeter (Nexis) 1 Nov. 11 The camera could tilt straight up while the orientable viewfinder 35 years ahead of its time remained in a fixed position.
2. Mathematics. Of a surface: such that an oriented figure, when moved around any closed path in the surface, returns to its initial position with the same orientation; not non-orientable; (more widely, of a manifold) capable of being assigned a well-defined global coordinate system.
ΘΚΠ
the world > relative properties > number > geometry > surface > [adjective]
monoid1863
anallagmatic1869
scrolar1869
torsal1869
closed1882
vicinal1895
orientable1920
non-orientable1925
1920 Bull. Amer. Math. Soc. 26 371 The manifold is said to be orientable if senses can be assigned to all the tetrahedral regions in such a way as to be consistent at every face.
1921 Ann. Math. 23 146 It is obvious that the manifold represented by the polygon is orientable or two-sided.
1949 S. Lefschetz Introd. Topol. ii. 82 Two orientable connected closed surfaces are homeomorphic if they have the same genus.
1952 P. Nemenyi tr. D. Hilbert & S. Cohn-Vossen Geom. & Imagination vi. 306 It can be demonstrated that all two-sided surfaces are orientable.
1968 A. H. Wallace Differential Topol. vi. 79 The sphere is orientable but the projective plane is not.
1975 W. M. Boothby Introd. Differentiable Manifolds v. 215 A manifold M is orientable if and only if it has a covering..of coherently oriented coordinate neighborhoods.
1990 Q. Jrnl. Math. 41 49 If H has orientable quotient space then the directions of period cycles are determined by adjusting the presentation obtained in [8] to satisfy (γ).
This entry has been updated (OED Third Edition, September 2004; most recently modified version published online March 2022).
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adj.1912