18-letter words containing o, r, i, s
- operating software — software used in the operation of a computer system, typically by performing such tasks as memory allocation, job scheduling, and input/output control
- operationalisation — Alternative spelling of operationalization.
- operations manager — business director
- optical disc drive — optical disk drive
- optical disk drive — (hardware) (Or "optical disc drive", "optical storage") A generic term for any device that reads and/or writes optical media, i.e. compact discs, DVDs and/or Blu-ray discs or future media that uses light (from a small laser) to read data off a removable, rotating disk. At least one such drive is commonly installed in most personal computers to allow them to play and/or record audio and video media and load and store data such as program installers. The floppy disk has been replaced by optical media due to its vastly greater capacity, e.g. 50,000 megabytes for a dual-layer blu-ray disc compared with 1.5 megabytes for a floppy (over 30,000 times as much).
- optical microscope — traditional magnifying instrument
- optical soundtrack — the final soundtrack on a motion picture, which appears as a band of black and white serrations along a strip of film to the left of the composite print. Light is shined through the serrations and is converted to audible sound.
- order of australia — an order awarded to Australians for outstanding achievement or for service to Australia or to humanity at large; established in 1975
- order room service — When a customer orders room service, they ask for meals or drinks to be brought to their room.
- organic solidarity — social cohesiveness that is based on division of labor and interdependence and is characteristic of complex, industrial societies.
- oriental alabaster — alabaster (def 2).
- oriental cat's-eye — a chatoyant variety of chrysoberyl, used as a gem.
- oriental scops owl — any of a group of small owls having ear tufts and a whistling call, especially Otus scops (Old World scops owl) and O. sunia (Oriental scops owl)
- oriental shorthair — any of a breed of domestic cat, similar to the Siamese but with greenish eyes and often a coat of a solid color
- orientation course — induction into sth
- orthopedic surgery — corrective operation on bones or joints
- orthotungstic acid — an oxyacid acid of tungsten. Formula: H2WO4
- oscillographically — By means of oscillography.
- osteitis deformans — Paget's disease.
- osteogenic sarcoma — osteosarcoma
- osteoradionecrosis — bone tissue death induced by radiation.
- outer automorphism — an automorphism that is not an inner automorphism.
- ovariohysterectomy — Surgical removal of the ovaries and uterus.
- over-conscientious — governed by conscience; controlled by or done according to one's inner sense of what is right; principled: She's a conscientious judge, who does not let personal prejudices influence her decisions.
- overdraft interest — interest charged on money withdrawn in excess of the credit balance of a bank or building society account
- overpressurization — pressure in excess of normal atmospheric pressure, as that caused by an explosion's shock wave or created in an accelerating airplane.
- overprotectiveness — unduly protective.
- overrepresentation — to give too much representation to; represent in numbers that are disproportionately high.
- overspecialization — excessive specialization, as in a field of study.
- ox-tongue partisan — a shafted weapon having a long, wide, tapering blade.
- pacinian corpuscle — (sometimes lowercase) a microscopic, onionlike body consisting of layers of connective tissue wrapped around a nerve ending, located in the deep layers of skin, tendons, etc., and functioning as a sensory receptor of pressure and vibration.
- pair of spectacles — a score of 0 in each innings of a match
- pairs championship — an event in a sport such as tennis or darts open to pairs of competitors
- parathyroid glands — any of several small oval glands usually lying near or embedded in the thyroid gland.
- passing-out parade — a ceremonial parade of cadets who have completed their training
- passive vocabulary — all the words, collectively, that a person can understand
- peasant proprietor — a peasant who owns land, especially the land he or she tills.
- pectoral sandpiper — an American sandpiper, Calidris melanotos, the male of which, when courting, inflates its chest conspicuously.
- pellitory of spain — a small Mediterranean plant, Anacyclus pyrethrum, the root of which contains an oil formerly used to relieve toothache: family Asteraceae (composites)
- pensioneer trustee — (in Britain) a person authorized by HMRC to oversee the management of a pension fund
- percussion flaking — a method of forming a flint tool by striking flakes from a stone core with another stone or a piece of bone or wood.
- percussion section — orchestra, group: drums, etc.
- percussion welding — a form of resistance welding in which the required pressure is provided by a hammerlike blow.
- perfect continuous — perfect progressive.
- performance artist — an artist that is involved in a theatrical presentation that incorporates various art forms, such as dance, sculpture, music, etc
- perish the thought — to die or be destroyed through violence, privation, etc.: to perish in an earthquake.
- pernicious anaemia — Pernicious anaemia is a very severe blood disease.
- personal assistant — aide
- personal exemption — Your personal exemption is the amount of money that is deducted from your gross income before you have to start paying income tax.
- personal insurance — insurance on personal risk, such as car insurance, health insurance or loss of earnings insurance