weld

American Heritage® Dictionary of the English Language, Fourth Edition

1. v. To join (metals) by applying heat, sometimes with pressure and sometimes with an intermediate or filler metal having a high melting point.
2. v. To bring into close association or union.
3. v. To be capable of being welded.
4. n. The union of two metal parts by welding.
5. n. The joint formed by welding.
6. n. See dyer's rocket.
7. n. The yellow dye obtained from dyer's rocket.

Century Dictionary and Cyclopedia

1. n. The dyer's-weed, Reseda luteola, a scentless species of mignonette, native in southern Europe and naturalized further north. It was formerly much cultivated as a dye-plant, its pods affording a permanent yellow suited to both animal and vegetable fibers, later displaced, however, by quercitron, flavin, and the aniline dyes. Its seeds yield a drying-oil. Also yellow-weed, and sometimes woad or wild woad.
2. To unite or consolidate, as pieces of metal or a metallic powder, by hammering or compression with or without previous softening by heat. Welding is and has long been a matter of great practical importance, chiefly in the manufacture of iron and steel, and of the various tools, utensils, and implements made of those metals. Iron has the valuable property of continuing in a kind of pasty condition through quite a wide range of temperature below its melting-point, and this is a circumstance highly favorable to the process of welding. Most metals, however, pass quickly, when sufficiently heated, from a solid to a liquid condition, and with such welding is more difficult. The term welding is more generally used when the junction of the pieces is effected without the actual fusing-point of the metal having been reached. Sheets of lead have sometimes been united together by fusing the metal with a blowpipe along the two edges in contact with each other, and this has been called autogenous soldering, or burning if the heating was done with a hot iron. Still, “the difference between welding and autogenous soldering is only one of degree” (Percy). The term welding is also used in speaking of the uniting of articles not metallic. Most metals when in the form of powder can be consolidated or welded into a perfectly homogeneous mass by sufficient pressure, without the aid of heat. The same is true of various non-metallic substances, such as graphite, coal, and probably many others. A method of welding has been recently invented by Elihu Thomson, which appears to be capable of being employed with a variety of metals on a very extensive scale. In this, which is known as electric welding, a current of electricity heats the abutting ends of the two objects which are to be welded, these being pressed together by mechanical force, and so arranged with reference to the electric current that there is a great and rapid accumulation of heat at the joint, in consequence of the greater relative conductivity of the rest of the circuit. This method of welding in some cases partakes of the nature of autogenous soldering, the pieces of metal being actually fused while uniting; in other cases, as with iron, nickel, or platinum, the union may take place without fusion, as in ordinary welding. In electric welding the pressure which forces the metallic surfaces together may, in the case of a plastic metal like iron, be either quiet or percussive in character; in autogenous soldering a more delicate and quiet Pressure is generally preferred. In case of large articles hydraulic pressure can be used to force their surfaces into contact with each other.
3. Figuratively, to bring into intimate union; make a close joining of: as, to weld together the parts of an argument.
4. To undergo the welding process; be capable of being welded.
5. n. A solid union of metallic pieces formed by welding; a welded junction or joint.
6. A Middle English form of wield.

Wiktionary

1. n. A herb (Reseda luteola) related to mignonette, growing in Europe, and to some extent in America, used to make a yellow dye; dyer's broom; dyer's rocket; dyer's weed; wild woad.
2. n. The yellow coloring matter or dye extracted from this plant.
3. v. transitive To bind together inseparably; to unite closely or intimately.
4. v. transitive To join two materials (especially two metals) together by applying heat, pressure and filler, either separately or in any combination.
5. n. The state of being welded.
6. n. The joint made by welding.
7. v. transitive (obsolete) To wield.

GNU Webster's 1913

1. v. obsolete To wield.
2. n. (Bot.) An herb (Reseda luteola) related to mignonette, growing in Europe, and to some extent in America; dyer's broom; dyer's rocket; dyer's weed; wild woad. It is used by dyers to give a yellow color.
3. n. Coloring matter or dye extracted from this plant.
4. v. To press or beat into intimate and permanent union, as two pieces of iron when heated almost to fusion.
5. v. Fig.: To unite closely or intimately.
6. n. The state of being welded; the joint made by welding.

WordNet 3.0

1. v. unite closely or intimately
2. n. European mignonette cultivated as a source of yellow dye; naturalized in North America
3. v. join together by heating
4. n. United States abolitionist (1803-1895)
5. n. a metal joint formed by softening with heat and fusing or hammering together