▪ I. mordant, n.
(ˈmɔːdənt)
Also 4 mourdant, 5–6 mordaunt.
[a. OF. mordant, subst. use of mordant adj.: see next.]
I. An instrument that ‘bites’ or holds fast.
† 1. A chape or tag of metal, sometimes jewelled, at the end of the pendant of a girdle. Obs.
| ? a 1366 Chaucer Rom. Rose 1094 The mourdant, wrought in noble wyse, Was of a stoon ful precious. c 1400 Laud Troy Bk. 8242 Eche man his coffer vnsperes And takes gerdeles of riche barres With bokeles of gold and fair pendaunt, Wel anamayled with the mordaunt. 1500 Will of Whiting (Somerset Ho.), A girdell of black silk..the pendaunt and the mordaunt ther of ys syluer. |
2. One of the nippers of a crab, lobster, etc.
| 1848 Johnston in Proc. Berw. Nat. Club II. No. 6. 300 The mandibular arms have a short..pincer, with a moveable nipper (mordant) placed above. |
II. 3. Dyeing. A substance used for fixing colouring matters on stuffs.
| 1791 Hamilton Berthollet's Dyeing Introd. 10 Mordants [serve] to render the colour more fixed. 1826 Henry Elem. Chem. II. 375 The latter class, however, may be durably attached by the mediation of what was formerly called a mordaunt, but has since been more properly termed, by the late Mr. Henry, a basis. 1865 Livingstone Zambesi i. 32 Columba root is said to be used as a mordant for certain colours. 1887 Manch. Courier 13 May 8/4 Turkey purple, which is made by substituting a mordant or basis of iron. |
| fig. 1809–10 Coleridge Friend (ed. 3) III. 131 The link or mordant by which philosophy becomes scientific and the sciences philosophical. 1864 Lowell Fireside Trav. 124 Practical application is the only mordant which will set things in the memory. |
b. Gilding. An adhesive compound for fixing gold-leaf.
| 1825 J. Nicholson Operat. Mechanic 748 Some prepare their mordants with Jew's pitch [etc.]... They employ it for gilding pale gold. 1881 Young Ev. Man his own Mechanic §1629 The principal mordants, or sizes, used by the gilder are known as gold size and fat-oil gold size. |
c. In Pathological laboratories (see quot.).
| 1891 Syd. Soc. Lex., Mordant. In Pathological investigations mordants are certain substances such as anilin oil, salicylic aldehyde, turpentine, carbolic acid, and borax, which are added to the basic anilin dyes to fix them on bacteria which may be present, and so render them more or less insensitive to decolourising agents. 1899 J. Cagney tr. Jaksch's Clin. Diagn. x. (ed. 4) 438. |
4. Etching. The fluid used to ‘bite in’ the lines on the plate.
| 1878 P. G. Hamerton in Encycl. Brit. VIII. 443/2 The nitrous mordant widens the lines; the Dutch mordant bites in depth. |
▪ II. mordant, a.
(ˈmɔːdənt)
Also 5, 9 mordent.
[a. F. mordant, pres. pple. of mordre to bite:—popular L. *mordĕre (= classical L. mordēre); the form mordent is assimilated to the L. pple. mordentem.]
Biting (in various senses).
1. Of satiric utterances (hence also of speakers or writers): Caustic, incisive.
| 1474 Caxton Chesse ii. v. (1481) d viij b, They ben..right mordent and bytyng detractours. 1858 Ellicott Destiny Creature (ed. 3) 22 A petty spirit of detraction, with unkindly words or mordant satire. 1881 Spectator 19 Nov. 1454/1 Lord Salisbury was, as usual, very mordant in his tone towards Mr. Gladstone. 1903 Blackw. Mag. July 12/2 He was endowed with a peculiarly mordant wit. |
2. Corrosive. Now rare.
| 1601 Holland Pliny I. 506 Of those marles which are found to be fat, the white is chiefe; and thereof be many sorts. The most mordant and sharpest of them all, is [etc.]. 1666 G. Harvey Morb. Angl. v. 61 The consumption of the kidneys is to be imputed to..mordant armoniack salt. |
| fig. 1870 Baldw. Brown Eccl. Truth 225 The mordant acid of what they were pleased to conceive of as pure reason. |
3. That causes pain or smart; pungent; biting. Of pain: acute, burning.
| a 1845 Syd. Smith Recipe for Salad 7 in Lady Holland Mem. (1855) I. 373 Of mordant mustard add a single spoon. 1876 G. Meredith Beauch. Career III. xii. 218 With a shadow of an elevation of her shoulders as if in apprehension of mordant pain. |
4. a. Having the property of fixing colouring matter or gold-leaf (see mordant n. 3, 3 b).
| 1825 J. Nicholson Operat. Mechanic 748 Mordant Varnish for Gilding. 1836 Penny Cycl. VI. 156/1 [Calico-printing.] Mordant reserves, which form the lapis lazuli style. 1847–64 in Webster. |
b. Of a dye: becoming fixed on the fibre as a result of forming an insoluble compound with a mordant.
| 1902 Encycl. Brit. XXVII. 559/2 Employed by themselves, Mordant Colours are usually of little or no value as dyestuffs, because..either they are not attracted by the fibre..or they only yield a more or less fugitive stain. Their importance and value as dyestuffs are due to the fact that they act like weak acids and have the property of combining with metallic oxides to form insoluble compounds termed ‘lakes’, which vary in colour according to the metallic oxide or salt employed. 1917 Fort & Lloyd Chem. Dyestuffs xiii. 112 Acid mordant dyes may be first dyed on wool like acid dyes and then after-chromed. 1940 Thorpe's Dict. Appl. Chem. (ed. 4) IV. 127/2 Mordant dyes rank amongst the oldest dyes used by mankind for colouring purposes. 1963 [see after-chrome a.]. 1965 E. Gurr Rational Use of Dyes in Biol. i. 115 Since sun yellow does not contain a hydroxyl group it cannot be classified as a mordant dye. |
5. In literal sense: Given to biting. rare.
| 1891 Bax Outlooks New Standp. iii. 174 Those who would take steps to restrain the mordant liberty of the cur, since they do not hold the doctrine of the divine right of dogs to bite. 1895 Pop. Sci. Monthly Sept. 652 The boy C― was for some time vigorously mordant in his angry fits. |
▪ III. mordant, v. Dyeing.
(ˈmɔːdənt)
[f. mordant n.]
trans. To impregnate with a mordant. Hence ˈmordanted ppl. a., ˈmordanting vbl. n. and ppl. a.
| 1836 Penny Cycl. VI. 153/2 The bath must be replenished with dung from time to time, as it gets exhausted by the passage of the mordanted goods. 1839 Ure Dict. Arts 195 Such stuffs must be galled, mordanted with alum..and cleared with a soap boil. 1877 O'Neill in Encycl. Brit. VII. 574/1 The cloth is mordanted by boiling it in a solution of salt of tin. Ibid., Owing to the decomposition of the mordanting salts. 1884 I. Levinstein in Manch. Exam. 6 Oct. 4/5 The preparing or mordanting of the stocking (before any dye whatever had been used). |
▪ IV. mordant
variant of mordent.