opening

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. The act or an instance of becoming open or being made to open.
2. n. An open space serving as a passage or gap.
3. n. A breach or aperture.
4. n. A clearing in the woods.
5. n. The first part or stage, as of a book.
6. n. The first performance: the opening of a play.
7. n. A formal commencement of operation: attended the opening of the new museum.
8. n. Games A specific pattern or series of beginning moves in certain games, especially chess.
9. n. An opportunity affording a chance of success. See Synonyms at opportunity.
10. n. An unfilled job or position; a vacancy.

Century Dictionary and Cyclopedia

1. n. The act of making open, in any sense of the verb open.
2. n. A beginning; an initial stage; commencement: as, the opening of a poem; also, dawn; first appearance.
3. n. A breach or gap; a hole or perforation; an aperture; specifically, in architecture, an unfilled part in a wall left for the purpose of admitting light, air, etc.
4. n. An open or clear space affording approach, entrance, or passage; an entrance.
5. n. A clear, unobstructed, or unoccupied space or place; specifically, in the United States, a tract over which there is a deficiency of forest, trees being not entirely wanting, but thinly scattered over the surface as compared with their abundance in an adjacent region. The word is most frequently used with this meaning in Wisconsin and neighboring States on the west, and as the scattered trees are frequently oaks (Quercus nigra, jack-oak, and Q. obtusiloba, post-oak, are the most common species), such openings are often designated as oak-openings. Similar tracts in the more southern States, especially in Kentucky, arc called barrens and oak-barrens.
6. n. A widening out of a crevice, in consequence of a softening or decomposition of the adjacent rock, which may still remain partly or wholly in its original position, or may have been entirely removed, so as to leave a vacant space of considerable width. In either case, the expanded crevice, or softened material in its vicinity, is called the opening. [Upper Mississippi lead region.]
7. n. An unoccupied place, position, course of action, business, etc., which may be entered, or the opportunity of entering it; a vacancy; an opportunity; a chance.
8. n. In law, the statement of the case made by counsel to the court or jury preliminary to adducing evidence: as, the opening for the plaintiff; the opening for the defendant. More specifically, the right to make such statement and adduce evidence before the adversary: as, if the defendant admits all the facts alleged, and only pleads new matter in defense, he has the opening.
9. n. In chess-playing, a mode of commencing a game; specifically, one of the numerous series of consecutive moves made at starting which are frequently played and which have been thoroughly investigated by chess analysts. In addition to the openings which involve a sacrifice of force for the sake of position, known as gambits (for which see gambit), the following are to be noted: Fianchetto, 1 P — K 4, P — QKt 3; Four Knights' game, 1 P — K 4, P — K 4; 2 Kt — KB 3, Kt — QB 3: 3 Kt — B 3, Kt — B 3; French game, 1 P — K 4, P — K 3; Giuoco Piano, 1 P — K 4, P — K 4; 2 Kt — KB 3, Kt — QB 3, 3 B — B 4, B — B 4; King's Bishop's opening, 1 P — K 4, P — K 4; 2 B — B 4; Knight's game of Ruy Lopez, 1 P — K 4, P — K 4; 2 Kt — KB 3, Kt — QB 3, 3 B — Kt 5; Petroff's defense, 1 P — K4, P — K 4; 2 Kt — KB 3, Kt — KB 3; Philidor's defense, 1 P — K 4, P — K 4; 2 Kt — KB 3, P — Q 3; Staunton's opening, 1 P — K 4, P — K 4; 2 Kt — KB 3, Kt — QB 3;3 P — B 3; Three Knights' game, 1 P — K 4, P — K 4; 2 Kt — KB 3, Kt — QB 3 (or Kt — KB 3); 3 Kt — B 3; Two Knights' defense, 1 P — K 4, P — K 4; 2 Kt — KB 3, Kt — QB 3; 3 B — B 4, Kt — B3; Vienna opening, 1 P — K 4, P — K 4; 2 Kt — QB 3.

Wiktionary

1. v. present participle of open.
2. n. An act or instance of making or becoming open.
3. n. Something that is open.
4. n. An act or instance of beginning.
5. n. Something that is a beginning.
6. n. A vacant position, especially in an array.
7. n. An opportunity, as in a competitive activity.
8. adj. cricket describing the first period of play, usually up to the fall of the first wicket; describing a batsman who opens the innings or a bowler who opens the attack

GNU Webster's 1913

1. n. The act or process of opening; a beginning; commencement; first appearance.
2. n. A place which is open; a breach; an aperture; a gap; cleft, or hole.
3. n. colloq. An opportunity.
4. n. A vacant place; a job which does not have a current occupant.
5. n. U.S. A thinly wooded space, without undergrowth, in the midst of a forest; a clearing.

WordNet 3.0

1. n. a recognized sequence of moves at the beginning of a game of chess
2. n. the initial part of the introduction
3. n. an entrance equipped with a hatch; especially a passageway between decks of a ship
4. n. the first of a series of actions
5. n. the first performance (as of a theatrical production)
6. n. an aperture or hole that opens into a bodily cavity
7. n. a ceremony accompanying the start of some enterprise
8. n. opportunity especially for employment or promotion
9. n. the act of opening something
10. n. a possible alternative
11. n. an open or empty space in or between things
12. n. a vacant or unobstructed space that is man-made
13. n. becoming open or being made open
14. adj. first or beginning