ns.
- without effective or enforced legal, commercial, or moral regulations: an open town.
- unguarded by an opponent: an open wide receiver.
- noting the part of the sea beyond headlands or enclosing areas of land: to sail on the open seas.
- free of ice, as a body of water or a seaport.
- free of navigational hazards: an open coast.
- (of a seaport) available for foreign trade;
not closed by government regulations or by considerations of health.
- (of a microphone) in operation;
- (of a delimiting punctuation mark) occurring at the beginning of a group of words or characters that is set off, as from surrounding text: open parenthesis; open quotes.Cf. close (def. 56).
- not yet balanced or adjusted, as an account.
- not constipated, as the bowels.
- (of a vowel) articulated with a relatively large opening above the tongue or with a relatively large oral aperture, as the vowel sound of cot compared with that in caught.
- (of a syllable) ending with a vowel.
- (of a consonant) continuant (opposed to stopped).
- [Ling.](of a class of items) readily admitting new members, as the class of nouns, verbs, or adjectives (opposed to closed).
- (of type) in outline form.
- widely spaced or leaded, as printed matter.
- (of an organ pipe) not closed at the far end.
- (of a string) not stopped by a finger.
- (of a note) produced by such a pipe or string or, on a wind instrument, without the aid of a slide, key, etc.
- (of an interval) containing neither endpoint.
- (of a set) consisting of points having neighborhoods wholly contained in the set, as the set of points within a circle.
- (of a map from one topological space to another) having the property that the image of an open set is an open set.
- free from frost;
mild or moderate: an open winter.
- (of a female animal) not pregnant.
- (of a fabric or weave) so loosely woven that spaces are visible between warp and filling yarns.
- to move (a door, window sash, etc.) from a shut or closed position so as to admit of passage.
- to render (a doorway, gateway, window, etc.) unobstructed by moving a door, window sash, etc., away from it.
- to render the interior of (a box, drawer, etc.) readily accessible.
- to clear (a passage, channel, etc.) of obstructions.
- to clear (areas or passages in the body).
- to give access to;
make accessible or available, as for use: to open a port for trade.
- to establish for business purposes or for public use: to open an office.
- to set in action, begin, start, or commence (sometimes fol. by up): to open a campaign.
- to uncover, lay bare, or expose to view.
- to expand, unfold, or spread out: to open a map.
- to make less compact, less closely spaced, or the like: to open ranks.
- to disclose, reveal, or divulge.
- to render accessible to knowledge, enlightenment, sympathy, etc.: to open one's mind.
- to cut, blast, or break into: to open a safe with nitro.
- to make or produce (an opening) by cutting or breaking, or by pushing aside or removing obstructions: to open a way through a crowd.
- to make an incision or opening in: to open a boil.
- to recall or revoke (a judgment, decree, etc.) for the purpose of allowing further contest or delay.
- to make the first statement of (a case) to the court or jury.
- [Cards.]to begin a hand by making (the first bid), placing (the first bet), or playing (a given card or suit) as the lead.
- to sail (a course) so that the apparent location of a distant fixed object changes with relation to a nearer fixed object (sometimes fol. by out).
- to become open, as a door, building, box, or enclosure.
- to afford access: a door that opens into a garden.
- to have an opening, passage, or outlet: The room opens into a corridor.
- (of a building, theater, etc.) to open its doors to the public: The museum opens at one o'clock.
- to begin a session or term, as a school.
- to begin a season, series of performances, or tour, as a theatrical company: The play will open in Boston.
- to begin, start, or commence an activity: The game opened with the national anthem.
- to part, or seem to part, so as to allow or reveal a passage: 