| forktail | <ornithology> One of several Asiatic and East Indian passerine birds, belonging to Enucurus, and allied genera. The tail is deeply forking. A salmon in its fourth year's growth. Source: Websters Dictionary (01 Mar 1998) |
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| forlorn | 1. Deserted abandoned; lost. "Of fortune and of hope at once forlorn." (Spenser) "Some say that ravens foster forlorn children." (Shak) 2. Destitute; helpless; in pitiful plight; wretched; miserable; almost hopeless; desperate. "For here forlorn and lost I tread." (Goldsmith) "The condition of the besieged in the mean time was forlorn in the extreme." (Prescott) "She cherished the forlorn hope that he was still living." (Thomson) A forlorn hope [D. Verloren hoop, prop, a lost band or troop; verloren, p.p. Of verliezen to lose + hoop band; akin to E. Heap. See For-, and Heap. A body of men (called in F. Enfants perdus, in G. Verloren posten) selected, usually from volunteers, to attempt a breach, scale the wall of a fortress, or perform other extraordinarily perilous service; also, a desperate case or enterprise. Synonym: Destitute, lost, abandoned, forsaken, solitary, helpless, friendless, hopeless, abject, wretched, miserable, pitiable. Origin: OE, p.p. Of forlesen to lose utterly, AS. Forleosan (p.p. Forloren); pref. For- + leosan (in comp) to lose; cf. D. Verliezen to lose, G. Verlieren, Sw. Forlora, Dan. Forloren, Goth. Fraliusan to lose. See For-, and Lorn, Lose. Source: Websters Dictionary (01 Mar 1998) |
| form | 1. <zoology> An infrasubspecific category which has no status in the classification code. 2. <suffix> In the form, shape of, mold; equivalent to -oid. See: morpho-. Origin: L. -formis, L. Forma (20 Jun 2000) |
| form perception | The sensory discrimination of a pattern shape or outline. (12 Dec 1998) |
| Formad's kidney | <nephrology> An enlarged and deformed kidney sometimes seen in chronic alcoholism. (05 Mar 2000) |
| Formad, Henry | <person> U.S. Physician, 1847-1892. See: Formad's kidney. (05 Mar 2000) |
| formal operations | <psychology> In the psychology of Piaget, a stage of development in thinking, occurring approximately between 11 and 15 years of age, during which a child becomes capable of reasoning about abstract situations; reasoning at this stage is comparable to that of normal adults but less sophisticated. (05 Mar 2000) |
| formaldehyde | <chemical> Commonly used fixative and antibacterial agent. As a fixative it is cheap and tends to cause less denaturation of proteins than does glutaraldehyde, particularly if used in a well buffered solution (buffered formalin, formal saline). Old formaldehyde solutions usually contain cross linking contaminants and it is therefore often preferable to used a formaldehyde generating agent such as paraformaldehyde. Formalin fumes, particularly in conjunction with hydrochloric acid vapour, are potently carcinogenic. (20 Jun 2000) |
| formaldehyde dismutase | <enzyme> Contains noncovalently bound nad(h); forms equimolar amounts of corresponding alcohols and acids from various aldehydes Registry number: EC 1.1.1.- (26 Jun 1999) |
| formaldehyde ferredoxin oxidoreductase | <enzyme> Contains molybdopterin as the organic component of tungsten cofactor Registry number: EC 1.2.7.- Synonym: hcho ferredoxin oxidoreductase (26 Jun 1999) |
| formaldehyde fixative | A widely used fixing agent for pathologic histology; the commercial solution is 37-40% formaldehyde and is known as 100% formalin or formol; a common impurity is formic acid, which must be neutralised or the fixative made in buffer solution; tissues fixed may have a pigment artifact precipitated. (05 Mar 2000) |
| formaldehyde reductase | <enzyme> Catalyses reduction of formaldehyde to methanol using NADH Registry number: EC 1.1.1.- (26 Jun 1999) |
| formaldehyde transketolase | <enzyme> From yeast; formaldehyde plus xylulose-5-phosphate yields glyceraldehydephosphate and dihydroxyacetone Registry number: EC 2.2.1.3 Synonym: dihydroxyacetone synthase (26 Jun 1999) |
| formalin | A 37% aqueous solution of formaldehyde. Synonym: formol. (05 Mar 2000) |
| formalin pigment | <chemistry> A pigment formed when acid aqueous solutions of formaldehyde act on blood-rich tissues; characterised by rotation of the plane of polarised light, withstanding extraction in aqueous and lipid solvents, being bleached in acids and hydrogen peroxide; not formed when tissue is fixed with formaldehyde buffered to pH levels above 6. (05 Mar 2000) |