fissileadj.
/ˈfɪsʌɪl/, /ˈfɪsl/, U.S. /ˈfɪs(ə)l/, /ˈfɪˌsaɪl/ 1. Capable of being divided or split; cleavable; inclined or tending to split.
ΘΚΠ
the world > matter > constitution of matter > weakness > [adjective] > brittle or fragile > fissile
findible1611
fissile1661
flaggy1847
the world > relative properties > wholeness > mutual relation of parts to whole > separation > action of dividing or divided condition > cleaving or splitting > [adjective] > cleft, split, or having clefts > able to be
fissile1661
cleavesome1674
cleavable1846
1661 R. Lovell Πανζωορυκτολογια, sive Panzoologicomineralogia Isagoge sig. E8v Some are Fissil, as the spectacle stone; others not, as mettals.
1756 C. Lucas Ess. Waters ii. 128 It springs slowly through a soft, fissil rock.
1830 C. Lyell Princ. Geol. I. xx. 346 The rock is whitened and becomes porous, fissile, and honeycombed, till at length it crumbles into a white siliceous powder.
a1856 H. Miller Testimony of Rocks (1857) xi. 427 They communicate often a fissile character to the stone in which they occur.
1887 C. Bowen tr. Virgil Æneid vi, in tr. Virgil in Eng. Verse 271 Ash-hewn timbers and fissile oaks with the wedges are rent.
2. Nuclear Physics. Capable of undergoing nuclear fission; sometimes used specifically of materials capable of fission upon absorption of a slow (as opposed to a fast) neutron.
ΘΚΠ
the world > matter > physics > atomic nucleus > nuclear fission > [adjective] > capable of fission
fissile1945
fissionable1945
1945 Nature 29 Dec. 768/1 The first bomb had not been dropped but..large production plants were rapidly accumulating the fissile material which it was planned to use.
1950 J. Cockcroft in Crammer & Peierls Atomic Energy iv. 75 Fast reactors require considerable quantities of scarce fissile material such as U 235.
1950 Amer. Speech 25 26 Fissile and fissionable..are sometimes distinguished, with fissile assigned to material that will undergo fission upon absorption of a neutron and fissionable reserved for material that fissions spontaneously.
1953 Economist 14 Nov. 508/1 These [‘breeder’ reactor] plants, which create fissile fuel out of normally non-fissile materials at a faster rate than they are used up, are in the early stage of development.
1957 Observer 7 July 11/8 The ‘gaseous diffusion’ process used during the war to separate fissile uranium-235 for atomic bombs from natural uranium was based on this work [of Professor S. Chapman].
1958 Listener 19 June 1005/1 There are fissile materials (such as plutonium, and uranium-235) which can undergo nuclear chain-reactions.
1965 G. R. Keepin Physics Nucl. Kinetics i. 3 We shall adopt the convention recommended by the American Nuclear Society. Thus ‘fissile’ will herein refer to those heavy nuclides which can be fissioned by thermal neutrons.
Derivatives
ˈfissileness n. = fissility n.
ΚΠ
1727 N. Bailey Universal Etymol. Eng. Dict. II Fissileness, aptness to be cleaved.
This entry has not yet been fully updated (first published 1896; most recently modified version published online March 2022).
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adj.1661