[open onto]{v. phr.} To have a view of. •/Our apartment in Chicago has a set of windows that open onto Lake Michigan./

[open Pandora’s box] See: PANDORA’S BOX.

[open question]{n. phr.} A debatable issue. •/Whether assisted suicide is legal and moral or not is still an open question, recent publicity on the matter notwithstanding./

[open secret]{n.} Something that is supposed to be a secret but that everyone knows. •/It is an open secret that Mary and John are engaged./ •/Who will be appointed as the next president of the college is an open secret./

[open sesame]{n. phr.}, {literary} Immediate means of entrance, or unobstructed access to something. •/Tom mistakenly believed that his wealth would be an open sesame to the world of creative arts./

[open shop]{n. phr.} A factory or firm that employs both union and non-union labor. •/The firm refuses to adopt an open shop policy./ Contrast: CLOSED SHOP.

[open the door]{v. phr.} To allow more action or discussion; give a chance. •/Learning to read and write opens the door to a better job and better living conditions./ •/Raising the tax rates will open the door to more help for older people./ Contrast: CLOSE THE DOOR. Compare: OPEN ITS DOORS.

[open the floodgates]{v. phr.} To let loose an outburst of human activity or emotion. •/It would open the floodgates of anger and discontent if the university raised tuition too soon./

[open up]{v.} 1. To show for the first time; make clear; reveal. •/The story of Helen Keller’s life opened up a whole new world to Mary./ •/Einstein’s theories opened up a whole new area for study./ 2. To make available; present an opportunity; offer. •/The building of the railroad opened up new lands to the pioneers./ •/John opened up a whole new section of the Scrabble board./ 3. {informal} To go faster. •/When they got out on the highway John opened up and drove at 65 miles per hour./ 4. {informal} To begin to shoot. •/When they got close to the enemy lines, they opened up with all they had./ 5. {informal} To begin to talk frankly. •/After John learned to trust Mr. Jones, he opened up and told him how he felt./ 6. To spread out. •/After a while the road opened up and they traveled more quickly./ 7. To become available. •/When she got her college diploma, many new jobs opened up./

[open up one’s eyes] See: OPEN ONE’S EYES.

[opinion] See: MATTER OP OPINION.

[opposite number]{n. phr.} A person occupying the same position as someone in a different group, organization, or country. •/The opposite number of the President of the United States in Germany is the Chancellor of the Federal Republic./

[opposite sex]{n. phr.} The sex different from the one being discussed or mentioned. •/Fred came out and said he was gay, having never had any interest in the opposite sex./

[optional origin]{n.} Stipulation in international commodities contract whereby the seller may ship from either his foreign or his domestic resources. •/Be sure to enter that in the books as an optional origin order./

[orbit] See: GO INTO ORBIT.

[order] See: APPLE-PIE-ORDER, CALL TO ORDER, IN ORDER, IN ORDER TO, IN SHORT ORDER, JUST WHAT THE DOCTOR ORDERED, MADE TO ORDER, OUT OF ORDER, PUT ONE’S HOUSE IN ORDER or SET ONE’S HOUSE IN ORDER, SHORT ORDER COOK, TO ORDER, WALKING PAPERS or WALKING ORDERS.

[order about] or [around] {v. phr.} To dictate arrogantly to someone; domineer. •/Dan orders his younger colleagues around in a most unpleasant way./

[ordinary] See: OUT OF THE ORDINARY.

[or other]{adv.} — Used to emphasize indefinite words or phrases beginning with "some" (as "someone", "something", "somewhere", "somehow", "sometime"). •/Somehow or other, Linda managed to get to the show on time./ •/I’ll think of something or other for the program./ •/She found a beautiful cup and saucer somewhere or other./ •/I’ll get around to cleaning the closets sometime or other./ •/Someone or other will take the letters to the post office./

[or so]{adv.} About; or a little more. •/Mr. Brown will be back in a day or so./ •/The book cost $5 or so./ •/There will be twenty or so people at the party./ Compare: MORE OR LESS.

[other] See: EACH OTHER, EVERY OTHER, GRASS IS ALWAYS GREENER ON THE OTHER SIDE OF THE FENCE or GRASS IS ALWAYS GREENER ON THE OTHER SIDE OF THE HILL, GO IN ONE EAR AND OUT THE OTHER, LAUGH ON THE WRONG SIDE OF ONE’S MOUTH or LAUGH ON THE OTHER SIDE OF ONE’S MOUTH, ON THE OTHER HAND, OR OTHER, SHOE ON THE OTHER FOOT, SIX OF ONE AND HALF-A-DOZEN OF THE OTHER, THIS AND THAT also THIS, THAT, AND THE OTHER, TURN THE OTHER CHEEK.

[other fish to fry]{n. phr.}, {informal} Other things to do; other plans. •/They wanted John to be the secretary, but he had other fish to fry./ •/Mary was invited to the party but she refused because she had other fish to fry./

[other side of the tracks] See: WRONG SIDE OF THE TRACKS.

[out and about] See: UP AND ABOUT.

[out-and-out]{adj.} Extreme; complete; thorough. •/The candidate was an out-and-out conservative./ •/It was out-and-out robbery to charge twice the usual price for eggs just because they were scarce./ Compare: THROUGH AND THROUGH.

[out at the elbows]{adj. phr.} Poorly or shabbily dressed. •/Roy walks around out at the elbows, but it’s not because he is penniless, but more in imitation of a certain style./

[out back]{adv. phr.} In one’s backyard. •/On the Fourth of July they were out back making preparations for their holiday barbecue./

[outback]{n.} 1. The remote and uncultivated wilderness areas of Australia or New Zealand, with very few inhabitants. •/Mike and Barbara roughed it in the Australian outback for nearly two years./ 2. Any remote, sparsely populated region. •/Tom’s old ranch in Texas is next to an arid outback./

[out cold]{adv.} or {adj.}, {informal} Unconscious; in a faint. •/The ball hit Dick in the head and knocked him out cold for ten minutes./ •/They tried to lift Mary when she fell down, but she was out cold./ Syn.: OUT LIKE A LIGHT(2). Compare: PASS OUT.

[outer space]{n.} What is outside of the earth’s air. •/An astronaut cannot live without oxygen when he goes into outer space./

[out for]{prep.} Joining, or planning to join; taking part in; competing for a place in. •/John is out for the basketball team./ •/Mary is going out for the school newspaper./ Compare: TRY OUT.

[out from under]{adj. phr.}, {informal} Free from something that worries you; seeing the end; finished. — Usually used with "be" or "get". •/Mary had so much to do in the new house she felt as though she would never be out from under./ •/John had so many debts, he couldn’t get out from under./

[out in force]{adv. phr.} Present in very large numbers; en masse. •/On the Fourth of July the police cars are out in force in the Chicago area./

[out in left field]{adj. phr.}, {informal} Far from the right answer; wrong; astray. •/Johnny tried to answer the teacher’s question but he was way out in left field./ •/Susan tried to guess what the surprise was but she was way out in left field./ 2. Speaking or acting very queerly; crazy. •/The girl next door was always queer, but after her father died, she was really out in left field and had to go to a hospital./ Compare: OUT OF ONE’S HEAD.