21-letter words containing h, e, d, r
- horns and halo effect — a tendency to allow one's judgement of another person, esp in a job interview, to be unduly influenced by an unfavourable (horns) or favourable (halo) first impression based on appearances
- hyperbolic paraboloid — a paraboloid that can be put into a position such that its sections parallel to one coordinate plane are hyperbolas, with its sections parallel to the other two coordinate planes being parabolas.
- hyperkinetic disorder — another name for attention deficit hyperactivity disorder (ADHD)
- indicated horse-power — the horsepower of a reciprocating engine as shown by an indicator record. Abbreviation: ihp, IHP.
- japanese stranglehold — a wrestling hold in which an opponent's wrists are pulled to cross his or her arms in front of his or her own neck and exert pressure on the windpipe
- jordan-holder theorem — the theorem that for any two composition series of a group, an isomorphism exists between the corresponding quotient groups of each series, taken in some specified order.
- joseph-marie jacquard — (person) /zhoh-zef' mah-ree' zhah-kar'/ (1752-07-07 to 1834-08-07) The inventor of the Jacquard loom.
- lactate dehydrogenase — an enzyme that catalyzes the interconversion of pyruvate and lactate, an important step in carbohydrate metabolism: elevated serum levels indicate injury to kidney, skeletal muscle, or heart muscle. Abbreviation: LDH.
- lady macbeth strategy — a strategy in a takeover battle in which a third party makes a bid acceptable to the target company, appearing to act as a white knight but subsequently joining forces with the original (unwelcome) bidder
- lambeth quadrilateral — the four essentials agreed upon at the Lambeth Conference of 1888 for a United Christian Church, namely, the Holy Scriptures, the Apostles' Creed, the sacraments of baptism and Holy Communion, and the historic episcopate
- lap and shoulder belt — a car seat belt
- 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.
- lordship of the isles — an overlordship of the Western Isles of Scotland and adjacent lands instituted in 1266 when Magnus of Norway ceded the Hebrides, the Isle of Man, and Kintyre to the King of Scotland, and claimed by the chiefs of Clan Dougall and later by those of Clan Donald. The title was forfeited to James IV in 1493 and is now held by the eldest son of the sovereign
- lost in the underflow — (jargon) Too small to be worth considering; more specifically, small beyond the limits of accuracy or measurement. This is a reference to "floating point underflow". The Hacker's Jargon File claimed that it is also a pun on "undertow" (a kind of fast, cold current that sometimes runs just offshore and can be dangerous to swimmers). "Well, sure, photon pressure from the stadium lights alters the path of a thrown baseball, but that effect gets lost in the underflow". Compare epsilon, epsilon squared; see also overflow bit.
- 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.
- medium dry white wine — Medium dry white wine is white wine that is not very sweet.
- member of the wedding — a novel (1946) and play (1950) by Carson McCullers.
- metopon hydrochloride — a narcotic drug, C18H21O3N·HCl, derived from morphine, but slightly more potent: used in medicine to relieve pain
- 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.
- 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-dichlorobenzene — a colorless liquid with a pleasant odor, C 6 H 4 Cl 2 , used as a solvent for a wide range of organic materials.
- 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.
- phillips screw-driver — a screw head having two partial slots crossed at right angles, driven by a special screwdriver (Phillips screwdriver)
- 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