| open sesame | any very successful means of achieving a result |
| open primary | a primary in which any registered voter can vote (but must vote for candidates of only one party) |
open frame
break | any frame in which a bowler fails to make a strike or spare, the break in the eighth frame cost him the match |
| open-heart surgery | heart surgery in which the rib cage is spread open, the heart is stopped and blood is detoured through a heart-lung machine while a heart valve or coronary artery is surgically repaired |
| fireplace hearth open fireplace | an open recess in a wall at the base of a chimney where a fire can be built, the fireplace was so large you could walk inside it, he laid a fire in the hearth and lit it, the hearth was black with the charcoal of many fires |
open-air market
open-air marketplace
market square | a public marketplace where food and merchandise is sold |
| open circuit | an incomplete electrical circuit in which no current flows |
open-end wrench
tappet wrench | a wrench having parallel jaws at fixed separation (often on both ends of the handle) |
| open-hearth furnace | a furnace for making steel in which the steel is placed on a shallow hearth and flames of burning gas and hot air play over it |
| open sight | rear gunsight having an open notch instead of a peephole or telescope |
| open weave | a weave in which warp threads never come together, leaving interstices in the fabric |
| open door | freedom of access, he maintained an open door for all employees |
open
surface | information that has become public, all the reports were out in the open, the facts had been brought to the surface |
open interval
unbounded interval | an interval that does not include its endpoints |
| open account | an unpaid credit order |
| open letter | a letter of protest, addressed to one person but intended for the general public |
open-door policy
open door | the policy of granting equal trade opportunities to all countries |
| open secret | something that is supposed to be secret but is generally known, their love affair was an open secret |
| open sesame | a magical command, used by Ali Baba |
| open | a tournament in which both professionals and amateurs may play |
open-face sandwich
open sandwich | sandwich without a covering slice of bread |
mutual fund
mutual fund company
open-end fund
open-end investment company | a regulated investment company with a pool of assets that regularly sells and redeems its shares |
| open shop | a company whose workers are hired without regard to their membership in a labor union |
| open house | an informal party of people with hospitality for all comers |
| Open University | a British university that is open to people without formal academic qualifications and where teaching is by correspondence or broadcasting or summer school |
| open society | a society that allows its members considerable freedom (as in a democracy), America's open society has made it an easy target for terrorists |
| open order | a military formation leaving enough space between ranks to allow an inspecting officer to pass |
outdoors
out-of-doors
open air
open | where the air is unconfined, he wanted to get outdoors a little, the concert was held in the open air, camping in the open |
| open clear | a clear or unobstructed space or expanse of land or water, finally broke out of the forest into the open |
| open chain | a chain of atoms in a molecule whose ends are not joined to form a ring |
open-end credit
revolving credit
charge account credit | a consumer credit line that can be used up to a certain limit or paid down at any time |
credit account
charge account
open account | credit extended by a business to a customer |
| open-hearth process | a process for making steel using an open-hearth furnace |
| open marriage | a marriage in which each partner is free to enter into extraneous sexual relationships without guilt or jealousy from the other |
chronic glaucoma
open-angle glaucoma | glaucoma caused by blockage of the canal of Schlemm, produces gradual loss of peripheral vision, open-angle glaucoma is the most common type of glaucoma |
compound fracture
open fracture | bone fracture associated with lacerated soft tissue or an open wound |
erupt irrupt flare up
flare break open
burst out | erupt or intensify suddenly, Unrest erupted in the country, Tempers flared at the meeting, The crowd irrupted into a burst of patriotism |
burst
split break open | come open suddenly and violently, as if from internal pressure, The bubble burst |
open
open up | make available, This opens up new possibilities |
| open open up | become available, an opportunity opened up |
| open up | talk freely and without inhibition |
| open | make the opening move, Kasparov opened with a standard opening |
open fire
fire | start firing a weapon |
open
open up
| cause to open or to become open, Mary opened the car door |
| break open | open with force, He broke open the picnic basket |
| click open | open with a clicking sound, These keys have clicked open many doors |
| open open up | become open, The door opened |
| fly open | come open suddenly, the doors flew open in the strong gust |
unfold
spread spread out open | spread out or open from a closed or folded state, open the map, spread your arms |
pioneer
open up | open up an area or prepare a way, She pioneered a graduate program for women students |