21-letter words containing a, d, h, r
- large hadron collider — a particle accelerator at the European Laboratory for Particle Physics near Geneva, containing a circular underground tunnel 27km (16.8 miles) in circumference, around which two streams of hadrons are sent in opposite directions before being brought together in a high-energy collision
- law of thermodynamics — any of three principles variously stated in equivalent forms, being the principle that the change of energy of a thermodynamic system is equal to the heat transferred minus the work done (first law of thermodynamics) the principle that no cyclic process is possible in which heat is absorbed from a reservoir at a single temperature and converted completely into mechanical work (second law of thermodynamics) and the principle that it is impossible to reduce the temperature of a system to absolute zero in a finite number of operations (third law of thermodynamics)
- light armored vehicle — an eight-wheeled armored reconnaissance car with a 25mm cannon, in service with the U.S. Army and Marine Corps in the 1980s.
- maidenhair spleenwort — an evergreen fern, Asplenium trichomanes, abundant in woody areas of the North Temperate Zone, having thickly clustered fronds.
- maître d'hôtel butter — melted butter mixed with parsley and lemon juice
- majority shareholding — a holding of more than half a company's shares
- maryland yellowthroat — (in former systems of nomenclature) the common yellowthroat, Geothlypis trichas, especially the eastern U.S. subspecies.
- mauvais quart d'heure — a brief unpleasant experience
- mechanical solidarity — social cohesiveness that is based on shared activities, beliefs, and experiences and is characteristic of simple traditional societies.
- modern apprenticeship — an arrangement that allows a school leaver to gain vocational qualifications while being trained in a job
- mohammed reza pahlavi — 1919-80; shah of Iran (1941-79); deposed
- monochloroacetic acid — chloroacetic acid.
- mother-of-pearl cloud — nacreous cloud.
- motherwell and wishaw — a burgh in the Motherwell district, in S Scotland.
- move heaven and earth — the abode of God, the angels, and the spirits of the righteous after death; the place or state of existence of the blessed after the mortal life.
- mucopolysaccharidoses — Plural form of mucopolysaccharidosis.
- mucopolysaccharidosis — Any of a group of metabolic disorders caused by the absence or malfunction of lysosomal enzymes needed to break down glycosaminoglycans.
- muhammad al-khwarizmi — Muhammad ibn Musa al-Khwarizmi
- muhammad riza pahlavi — Pahlavi (def 1).
- munchausen's syndrome — a mental disorder in which a patient feigns illness to obtain hospital treatment
- near-death experience — A near-death experience is a strange experience that some people who have nearly died say they had when they were unconscious.
- neither hide nor hair — nothing whatsoever
- northumberland strait — the part of the Gulf of St. Lawrence that separates Prince Edward Island from New Brunswick and Nova Scotia, in SE Canada. About 200 miles (320 km) long; 9–30 miles (15–48 km) wide.
- not hold one's breath — If you say that you won't hold your breath, you mean that you do not expect something to happen even though someone has suggested that it might.
- of time and the river — a novel (1935) by Thomas Wolfe.
- old spanish practices — irregular practices among a group of workers to gain increased financial allowances, reduced working hours, etc
- one thing and another — You can use the expression 'one thing and another' to suggest that there are several reasons for something or several items on a list, but you are not going to explain or mention them all.
- ortho-phosphoric acid — a colorless, crystalline solid, H 3 PO 4 , the tribasic acid of pentavalent phosphorus: used chiefly in fertilizers, as a source of phosphorus salts, and in soft drinks as an acidulant and flavoring agent.
- orthophosphorous acid — a white to yellowish, crystalline, hygroscopic, water-soluble solid, H 3 PO 3 , used chiefly in the synthesis of phosphites.
- overhead-valve engine — I-head engine.
- pass the hat (around) — In British English, if you pass the hat around, you collect money from a group of people, for example in order to give someone a present. In American English, you just say pass the hat.
- pathfinder prospectus — a prospectus regarding the flotation of a new company that contains only sufficient details to test the market reaction
- phenarsazine chloride — adamsite.
- philadelphia scrapple — a superior variety of scrapple made with pork shoulder and other cuts of pork rather than with pork scraps.
- pipelined burst cache — Pipeline Burst Cache
- ploughman's spikenard — a European plant, Inula conyza, with tubular yellowish flower heads surrounded by purple bracts: family Asteraceae (composites)
- populist shop steward — a shop steward who operates in a delegate role, putting the immediate interests of his members before union principles and policies
- privacy enhanced mail —
- programmed cell death — a normal, genetically regulated process leading to the death of cells and triggered by the presence or absence of certain stimuli, as DNA damage.
- propantheline bromide — a substance, C 2 3 H 3 0 BrNO 3 , used in the treatment of peptic ulcers.
- pseudohermaphroditism — an individual having internal reproductive organs of one sex and external sexual characteristics resembling those of the other sex or being ambiguous in nature. Compare hermaphrodite (def 1).
- psychopathic disorder — (in England, according to the Mental Health Act 1983) a persistent disorder or disability of mind which results in abnormally aggressive or seriously irresponsible conduct on the part of the person concerned
- purchasing department — the group of staff within an organization that is responsible for buying goods or products
- put in the hard yards — to make a great effort to achieve an end
- ralph roister doister — a play (1553?) by Nicholas Udall: the earliest known English comedy.
- rayleigh distribution — (mathematics) A curve that yields a good approximation to the actual labour curves on software projects.
- reading comprehension — a text that students use to help them improve their reading skills, by reading it and answering questions relating to the text. Sometimes used as a test or examination of reading skills. A reading comprehension can be in the student's own or another language
- record of achievement — a statement of the personal and educational development of each pupil
- red-headed woodpecker — a black and white North American woodpecker, Melanerpes erythrocephalus, having a red head and neck.
- redlegged grasshopper — a migratory grasshopper, Melanoplus femur-rubrum, of the southwestern and midwestern U.S., having reddish skin on the underside of the hind legs: an agricultural pest.