Forms: 6–7 clamme, 9 clamm, 1, 5– clam. [OE. clam(m, clǫm(m, corresp. to MHG. klam, Ger. klamm cramp, fetter, constriction, pinching, and, with change of gender, OHG. chlamma, MHG. klamme in same sense. Cf. also MHG., Ger. klemme, Du. klemme, klem, app. from type *klam(m)jôn-. See also CLEM v.
These point to an OTeut. *klam-, *klamm-, or *klamb-, to press or squeeze together. Some compare *klam- with pre-Teut. glom- in Lat. glomus. But Sievers inclines to start from klimb- in OE. climban, Ger. klimmen to CLIMB, orig. to cleave, cling or adhere; thence an adj. *klambo- sticky, with causal vb. *klambjan ‘to make to stick, press, compress.’ This would provide a common source for the first four sbs. spelt CLAM, and the first three spelt CLAMP, with the adjs. and verbs belonging to both series.]
† 1. Anything that holds tight; bond, chain; pl. bonds, bondage. Obs. (In OE.)
971. Blickl. Hom., 83. Þe Drihten of deaþe aras … æfter þæm clammum helle Þeostra.
a. 1000. Andreas (Gr.), 130. Þa þe on carcerne, clommum fæste … hwile wunedon.
a. 1000. Riddles, xliii. 12 (Gr.). Hwylc þæs hordgates cæʓan cræfte þa clamme onleac.
2. An instrument or mechanical device for clasping rigidly or otherwise holding fast; e.g., a clamp for holding two stones together, or any instrument of the nature of a vice or pair of pincers that holds things between its jaws. With many special technical applications in different trades and branches of industry, in some of which it varies with CLAMP. See the quots.
1399. Fabric Rolls York Minster (Surtees), 19. Item ij soudyngirenes j par de clames et j par de tanges, precii 4d.
1496. Bk. St. Albans, Fishing, 14. [Hokis] for whoos makyng ye must haue fete fyles … A semy clam of yren … a payre of longe and smalle tongys, [etc.].
1512. Test. Ebor., V. (Surtees), 35. (in ‘The Shoppe’) A par of clamez, ijd.
1547. Ludlow Churchw. Acc. (Camd. Soc.), 29. For iiij. clammes for the pascalle bordes.
1638. Churchw. Acc. Kirton in Lindsey, in Proc. Soc. Antiq. (1864), 14 April. For iiij poales for the clammes and to John Dawber for shafting them, iijs. iiijd.
1832. Babbage, Econ. Manuf., xix. (ed. 3), 188. Another pair of forceps now removes the pin to another pair of clams.
1868. G. Macdonald, R. Falconer, I. 136. Alexander … had the upper leather of a boot in the grasp of the clams.
1869. Echo, 26 Jan. They [poachers] were seen to place the clams over the rabbit holes and to put the ferrets into two of them.
1884. F. J. Britten, Watch & Clockm., 26. The round wire is … drawn through jewelled clams.
1886. S. W. Lincoln. Gloss. (E. D. S.), Clams or Clems, wooden instruments, with which shoemakers or saddlers clip their leather to hold it fast.
1887. Kent. Gloss. (E. D. S.), Clam, a rat-trap, like a gin.
b. A movable cheek or protective lining placed in the jaws of a vice.
1879. Cassell’s Techn. Educ., IV. 414/1. Holding it with convenient clams in his vice.
1888. Sheffield Gloss. (E. D. S.), Clam, leather, paper, or lead linings for the jaws of a vice.
c. pl. ‘An instrument resembling a forceps employed in weighing gold’ (Jamieson).
1790. Shirrefs, Poems, 360 (Jam.). The brightest gold that e’er I saw Was grippet in the clams.
d. ‘A kind of forceps used for bringing up specimens of the [sea-]bottom in sounding; a drag’ (Smyth, Sailor’s Word-bk., s.v. clams).
1821. A. Fisher, Voy. Arct. Reg., 17. Tied to the sounding line at … ten fathoms from the lead, or rather the claim. (note This instrument is intended to bring up a greater quantity of sounding than the usual arming of the lead.) Ibid., 65. The deep-sea-clamm was used on this occasion, the soundings brought up, consisted chiefly of mud, intermixed with small stones.
† 3. pl. Clutches, claws. Obs.
a. 1569. Kyngesmill, Man’s Est., xiv. (1580), 118. To plucke man out of the bloody clammes of that ravenyng Lyon Sathan.
1574. E. Hake, Touchstone, B iij b. Luckish loytering lubbers [who] doo keepe within their clammes the livelyhood of true pastors and painful laborers.
4. Theat. An instrument formed of two parallel pieces of board fastened at one end by a handle, used in pantomimes as a noisy sort of cudgel.
