*fiss*

n. [ See Diffind. ] Act of cleaving or splitting. [ R. ] Bailey. [ 1913 Webster ]

n. [ L. fissus (p. p. of findere to split) + E. gemmation. ] (Biol.) A process of reproduction intermediate between fission and gemmation. [ 1913 Webster ]

a. [ L. fissilis, fr. fissus, p. p. of findere to split. See Fissure. ] 1. Capable of being split, cleft, or divided in the direction of the grain, like wood, or along natural planes of cleavage, like crystals. [ 1913 Webster ]

This crystal is a pellucid, fissile stone. Sir I. Newton. [ 1913 Webster ]

2. Fissionable. [ PJC ]

a. [ L. fissus (p. p. of findere to split) + E. lingual. ] (Zool.) Having the tongue forked. [ 1913 Webster ]

‖n. pl. [ NL., fr. L. fissus (p. p. o f findere to split) + lingua tongue. ] (Zool.) A group of Lacertilia having the tongue forked, including the common lizards. [ Written also Fissilingues. ] [ 1913 Webster ]

n. Quality of being fissile. [ 1913 Webster ]

n. [ L. fissio. See Fissure. ] 1. A cleaving, splitting, or breaking up into parts. [ 1913 Webster ]

2. (Biol.) A method of asexual reproduction among the lowest (unicellular) organisms by means of a process of self-division, consisting of gradual division or cleavage of the into two parts, each of which then becomes a separate and independent organisms; as when a cell in an animal or plant, or its germ, undergoes a spontaneous division, and the parts again subdivide. See Segmentation, and Cell division, under Division. [ 1913 Webster ]

3. (Zool.) A process by which certain coral polyps, echinoderms, annelids, etc., spontaneously subdivide, each individual thus forming two or more new ones. See Strobilation. [ 1913 Webster ]

4. (Physics) The act or process of disintegration of an atomic nucleus into two or more smaller pieces; called also nuclear fission. The process may be spontaneous or induced by capture of neutrons or other smaller nuclei, and usually proceeds with evolution of energy. [ PJC ]

a. Capable of undergoing nuclear fission; -- a property of certain isotopes of elements with heavy nuclei.
Syn. -- fissile. [ PJC ]

a. [ L. fissus (p. p. of findere to split) + palma palm. ] (Zool.) Semipalmate and loboped, as a grebe's foot. See Illust. under Aves. [ 1913 Webster ]

‖n. pl. [ NL. See Fissiparous. ] (Zool.) Animals which reproduce by fission. [ 1913 Webster ]

n. [ See Fissiparous. ] (Biol.) Reproduction by spontaneous fission. [ 1913 Webster ]

n. (Biol.) Quality of being fissiparous; fissiparism. [ 1913 Webster ]

a. [ L. fissus (p. p. of findere to split) + parere to bring forth: cf. F. fissipare. ] (Biol.) Reproducing by spontaneous fission. See Fission. -- Fis*sip"a*rous*ly, adv. [1913 Webster]

n. (Biol.) Reproduction by fission; fissiparism.

n. (Zool.) One of the Fissipedia. [ 1913 Webster ]

{ , a. [ Cf. F. fissipède. ] (Zool.) Having the toes separated to the base. [ See Aves. ] [ 1913 Webster ]

‖n. pl. [ NL., fr. L. fissus (p. p. of findere to cleave) + pes, pedis, a foot. ] (Zool.) A division of the Carnivora, including the dogs, cats, and bears, in which the feet are not webbed; -- opposed to Pinnipedia. [ 1913 Webster ]

a. [ Cf. F. fissirostre. ] (Zool.) Having the bill cleft beyond the horny part, as in the case of swallows and goatsuckers. [ 1913 Webster ]

‖n. pl. [ NL., fr. L. fissus (p. p. of findere to cleave) + rostrum beak. ] (Zool.) A group of birds having the bill deeply cleft. [ 1913 Webster ]

a. Pertaining to a fissure or fissures; as, the fissural pattern of a brain. [ 1913 Webster ]

n. (Anat.) The act of dividing or opening; the state of being fissured. [ 1913 Webster ]

n. [ L. fissura, fr. findere, fissum, to cleave, split; akin to E. bite: cf. F. fissure. ] A narrow opening, made by the parting of any substance; a cleft; as, the fissure of a rock. [ 1913 Webster ]

Cerebral fissures (Anat.), the furrows or clefts by which the surface of the cerebrum is divided; esp., the furrows first formed by the infolding of the whole wall of the cerebrum. --
Fissure needle (Surg.), a spiral needle for catching together the gaping lips of wounds. Knight. --
Fissure of rolando (Anat.), the furrow separating the frontal from the parietal lobe in the cerebrum. --
Fissure of Sylvius (Anat.), a deep cerebral fissure separating the frontal from the temporal lobe. See Illust. under Brain. --
Fissure vein (Mining), a crack in the earth's surface filled with mineral matter. Raymond. [ 1913 Webster ]

v. t. To cleave; to divide; to crack or fracture. [ 1913 Webster ]

‖n. [ NL., dim. of L. fissura a fissure. ] (Zool.) A genus of marine gastropod mollusks, having a conical or limpetlike shell, with an opening at the apex; -- called also keyhole limpet. [ 1913 Webster ]

n. a natural family of marine limpets.
Syn. -- family Fissurellidae. [ WordNet 1.5 ]

adj. not fissile. Opposite of fissile. [ WordNet 1.5 ]

adj. (Physics) not capable of undergoing fission{ 4 }; -- of atoms or chemical elements. Opposite of fissionable. [ WordNet 1.5 ]