isochronous, a.
(aɪˈsɒkrənəs)
[f. as isochron-al + -ous.]
1. a. Taking place in or occupying equal times; equal in metrical length; equal in duration, or in intervals of occurrence, as the vibrations of a pendulum; characterized by or relating to vibrations or motions of equal duration; vibrating uniformly, as a pendulum. spec. in Prosody, equal in metrical length.
| 1706 Phillips s.v. Isochrone, The Vibrations or Swings of a Pendulum, or hanging Weight, that are made in the same Space of Time, are said to be Isochronous. 1748 Hartley Observ. Man i. ii. 119 Vibratory Motions of different Lengths can be isochronous only according to one Law. 1784 Seale Grk. Metres (L.), The tribrach and iambic are isochronous. 1789 Burney Hist. Mus. III. i. 31 The poetical measures..when sung in the drawling and isochronous manner afford the ear no pleasure. 1822 Southey Poet. Wks. (1853) Pref. 23/2 If the English verse is not isochronous with the Latin, it must be shorter. 1825 J. Nicholson Operat. Mechanic 516 The great object of the escapement is to preserve this isochronous motion of the pendulum. 1857 C. Patmore in North Brit. Rev. XXVII. 149 A metre which, totally abandoning the element of natural syllabic quantity, takes the isochronous bar for the metrical integer. 1884 F. J. Britten Watch & Clockm. 126 A balance spring is said to be isochronous when it causes both the long and short arcs of the balance to be performed in the same time. 1942 J. C. Pope Rhythm of Beowulf 9 Isochronous measures are the rule..and it is easy to produce them in Beowulf by means of limited quantitative variation. 1948 Mod. Philology XLVI. 75 There is..no reason to suppose that, if the Beowulf was chanted to a real musical accompaniment, the lines were therefore delivered in isochronous groups. 1971 Times Lit. Suppl. 1 Oct. 1179/3 Its technique of isochronous rhythm—a metrical sequence which remains constant for a given part, though the pitch relationships change—is comparable with the Oriental tala. |
b. Taking place (vibrating, etc.) in the same time, or at the same intervals of time, as something else; equal in duration (vibration-period, etc.) to or with something.
| 1776 Cavallo in Phil. Trans. LXVI. 410 The snappings..seemed at first isochronous with the shocks I had received. 1854 Jones & Siev. Pathol. Anat. (1874) 415 The tumour..offers a pulsation to the touch isochronous with the arterial pulse. 1879 G. B. Prescott Sp. Telephone 129 There follows..a series of oscillations, which are isochronous with the intermittence of the current. |
2. Palæont. [ad. G. isochron (E. Mojsisovics Die Cephalopoden der Hallstätter Kalke (1893) II. 5).] Originating or formed at the same period.
| 1895 [see homœomorphy]. 1913 [see heterochronous a. b]. 1952 R. C. Moore et al. Invertebr. Fossils vi. 218/1 Such contemporaneous or near-contemporaneous forms he [sc. Buckman] designated as isochronous homeomorphs. |
Hence iˈsochronously adv., in an isochronous manner; in equal times.
| 1748 Hartley Observ. Man. i. ii. 238 The Membrane will be fitted to vibrate isochronously with the several Tones. 1833 Wheatstone in Phil. Trans. 596 The resultants of very simple modes of vibration oscillating isochronously. |