open fireplace
— Noun
– English
～ 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 door
— Noun
– English
～ the policy of granting equal trade opportunities to all countries
open air
— Noun
– English
～ 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-hearth furnace
— Noun
– English
～ 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 marriage
— Noun
– English
～ a marriage in which each partner is free to enter into extraneous sexual relationships without guilt or jealousy from the other
open-end credit
— Noun
– English
～ a consumer credit line that can be used up to a certain limit or paid down at any time
open circuit
— Noun
– English
～ an incomplete electrical circuit in which no current flows
open
— Noun
– English
～ a tournament in which both professionals and amateurs may play
open interval
— Noun
– English
～ an interval that does not include its endpoints