From the second edition (1989):

asymmetry

(əˈsɪmɛtrɪ) [ad. Gr. ἀσυµµετρία, n. of quality f. ἀσύµµετρος: see symmetry.]

1. Math. The relation of two quantities which have no common measure, as 1 and √2; incommensurability. ? Obs.

a1652 J. Smith Sel. Disc. 4. 100 Equality, proportion, symmetry and assymmetry of magnitudes. 1675 Collins in Rigaud Corr. Sci. Men II. 264 The method of shunning asymmetries mentioned in Des Cartes. 1796 in Hutton Math. Dict. I. 162.

2. a. Want of symmetry, defective correspondence between things or their parts, disproportion.

1664 Evelyn Freart's Archit. Ep. Ded. 8 The asymmetrie of our Buildings. 1672 J. Worthington in Mede's Wks. Introd. 32 There was an asymmetry and disproportion in the subservient Faculties. 1877 Huxley Anat. Inv. An. viii. 530 Male Cephalopods are distinguished‥by the asymmetry of their arms. 1948 Glasstone Physical Chem. xii. 904 The influence on the velocity of the ion is known as the relaxation effect, or sometimes as the asymmetry effect, because it arises from the lack of symmetry in the electrical atmosphere of a moving ion.

b. Chem. Lack of symmetry in the spatial arrangement of atoms or groups in a molecule; = stereo-isomerism.

1875 Jrnl. Chem. Soc. XXVIII. 862 He [sc. J. H. van't Hoff] has deduced the following rules.‥ Derivatives of optically active combinations lose their rotatory power when the asymmetry of their carbon-atoms disappears. 1885 Encycl. Brit. XIX. 314/1 What peculiarity of constitution can give a molecule this helicoidal asymmetry? 1902 Ibid. XXVI. 721/1 The doctrine of asymmetry may be extended to elements other than carbon. 1959 Chambers's Encycl. III. 357/2 When two of the four attached groups are similar, as in propionic acid,‥the asymmetry vanishes together with the possibility of optical isomerism.