[f. next + -ITY, or a. F. variabilité, = It. variabilità, Sp. variabilidad, Pg. -idade.]
1. The fact or quality of being variable in some respect; tendency towards, capacity for, variation or change.
1721. Mrs. Griffith, Hist. Lady Barton, I. 29. In her outward appearance there is a variability, that renders it almost impossible to draw an exact resemblance of her.
1796. Burke, Regic. Peace, Wks. 1842, II. 355. His protest against binding him to his opinions, and his reservation of a right to whatever opinions he pleases, remain in their full force. This variability is pleasant, and shews a fertility of fancy.
1839. Lady Lytton, Cheveley, III. 146. It is this atmospheric variability … that occasions the thousand little dissensions that spring from love itself.
1869. Phillips, Vesuv., viii. 246. Reasonings on the variability of the relative level of land and sea.
1885. Contemp. Rev., June, 901. They made too little account of the variability of human nature and circumstances.
2. spec. a. The fact of, or capacity for, varying in amount, magnitude or value.
1816. trans. Lacroix’s Diff. & Int. Calculus, 157. From this may be deduced the differential coefficient of z, relative to the variability of x.
1870. Phipson, trans. Guillemin’s Sun, 282. The variability of a certain number of stars.
1873. H. Spencer, Sociol., vi. 124. The variability of the ratio … being duly conceived in terms of lines that lengthen and shorten.
b. Biol. Capability in plants or animals of variation or deviation from a type.
1832. Lyell, Princ. Geol. (1835), II. 449. Variability of a species compared to that of an individual.
1859. Darwin, Orig. Spec., i. 40. A high degree of variability is obviously favourable, as freely giving the materials for selection to work on.
1880. A. R. Wallace, Island Life, iv. 58. The belief in the variability of all animals in all their parts and organs.
