13-letter words containing b, t, r
- octane number — (of gasoline) a designation of antiknock quality, numerically equal to the percentage of isooctane by volume in a mixture of isooctane and normal heptane that matches the given gasoline in antiknock characteristics.
- offertory box — the box or container where worshippers' put their offerings (usually money)
- open brethren — one of the two main divisions of the Plymouth Brethren that, in contrast to the Exclusive Brethren, permits contacts with members outside the sect
- open-timbered — constructed so that the timbers are exposed.
- opisthobranch — any gastropod mollusk of the order Opisthobranchia, as the sea slugs, sea butterflies, and sea hares, characterized by a vestigial or absent mantle and shell and two pairs of tentacles.
- optical fiber — optical fibre
- optical fibre — (communications) (fibre optics, FO, US "fiber", light pipe) A plastic or glass (silicon dioxide) fibre no thicker than a human hair used to transmit information using infra-red or even visible light as the carrier (usually a laser). The light beam is an electromagnetic signal with a frequency in the range of 10^14 to 10^15 Hertz. Optical fibre is less susceptible to external noise than other transmission media, and is cheaper to make than copper wire, but it is much more difficult to connect. Optical fibres are difficult to tamper with (to monitor or inject data in the middle of a connection), making them appropriate for secure communications. The light beams do not escape from the medium because the material used provides total internal reflection. See also FDDI, Optical Carrier n, SONET.
- ora et labora — pray and work
- orbital index — the ratio of the maximum breadth to the maximum height of the orbital cavity multiplied by 100.
- orbitofrontal — Located in the frontal lobes above the orbits of the eyes.
- ornithophobia — Fear of birds.
- osteofibrosis — loss of calcium from the bones, causing them to become fragile
- ostrobogulous — (humorous) Slightly risqu\u00e9 or indecent; bizarre, interesting, or unusual.
- out of breath — the air inhaled and exhaled in respiration.
- outward bound — (in Britain) a scheme to provide adventure training for young people
- outward-bound — headed in an outward direction, as toward foreign ports: We passed an outward-bound ship as we came into the harbor.
- over-abstract — thought of apart from concrete realities, specific objects, or actual instances: an abstract idea.
- over-abundant — an excessive amount or abundance; surfeit: an overabundance of sugar in the diet.
- overambitious — having ambition; eagerly desirous of achieving or obtaining success, power, wealth, a specific goal, etc.: ambitious students.
- overbreathing — hyperventilation
- overelaborate — excessively or fussily elaborate, ornate, detailed, etc.
- overexcitable — Excessively excitable.
- overexuberant — effusively and almost uninhibitedly enthusiastic; lavishly abundant: an exuberant welcome for the hero.
- overnight bag — a travel bag large enough to hold personal articles and clothing for an overnight trip.
- overstability — the state of being excessively stable
- owl butterfly — any of several South American nymphalid butterflies of the genus Caligo, especially C. eurylochus, having a spot like an owl's eye on each hind wing.
- parietal bone — either of a pair of membrane bones forming, by their union at the sagittal suture, part of the sides and top of the skull.
- parietal lobe — the middle part of each cerebral hemisphere behind the central sulcus.
- parking orbit — a temporary orbit in which a spacecraft awaits the next phase of its mission.
- parrot's-bill — a showy, vinelike plant, Clianthus puniceus, of New Zealand, having clusters of eight white-streaked, crimson flowers.
- parsons table — a square or rectangular table, often of lightweight material, with straight legs that are square in cross section and of the same thickness as the top extending from the corners flush with the top so as to appear jointless.
- particle beam — Physics. a concentrated stream of particles, as electrons, neutrons, or protons, generated for studying particle interactions, nuclear structure, crystal structure, etc.
- particleboard — a boardlike building material made by compressing sawdust or wood particles with a resin binder
- partitionable — a division into or distribution in portions or shares.
- path-breaking — very original; ground-breaking
- peanut butter — a paste made from ground roasted peanuts, used as a spread or in cookery.
- pebble heater — a heat exchanger utilizing refractory pellets to store and give off heat.
- pentobarbital — a barbiturate, C 1 1 H 1 7 N 2 O 3 , used as a hypnotic and as a sedative.
- perambulation — to walk through, about, or over; travel through; traverse.
- perditionable — deserving perdition or damnation
- perishability — subject to decay, ruin, or destruction: perishable fruits and vegetables.
- personal best — A sports player's personal best is the highest score or fastest time that they have ever achieved.
- phenobarbital — a white, crystalline powder, C 1 2 H 1 2 N 2 O 3 , used as a sedative, a hypnotic, and as an antispasmodic in epilepsy.
- pigeon breast — chicken breast.
- plant breeder — a botanist concerned with the origin and evolution of plants
- pleasure boat — recreational vessel
- polycarbonate — a synthetic thermoplastic resin, a linear polymer of carbonic acid, used for molded products, films, and nonbreakable windows.
- port colborne — a city in SE Ontario, in S Canada.
- post-cambrian — Geology. noting or pertaining to a period of the Paleozoic Era, occurring from 570 million to 500 million years ago, when algae and marine invertebrates were the predominant form of life.
- postbourgeois — (in Marxist thought) belonging to a period of society after the decline of the bourgeoisie