21-letter words containing r, h
- purple-fringed orchid — either of two orchids, Habenaria fimbriata or H. psycodes, of eastern North America, having a cluster of fragrant purple flowers with a fringed lip.
- purple-fringed orchis — either of two North American orchids (Habenaria psycodes and H. fimbriata) with purple-fringed flowers
- put in the hard yards — to make a great effort to achieve an end
- put sb in the picture — If you put someone in the picture, you tell them about a situation which they need to know about.
- put sb in their place — If you put someone in their place, you show them that they are less important or clever than they think they are.
- put something over on — to deceive; trick
- queer someone's pitch — to upset someone's plans
- ralph roister doister — a play (1553?) by Nicholas Udall: the earliest known English comedy.
- rap over the knuckles — to reprimand
- 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
- reciprocal inhibition — the theory that the pairing of an anxiety-provoking stimulus with anxiety-reducing reactions will weaken the association between the stimulus and the anxiety.
- recompression chamber — hyperbaric chamber.
- reconnaissance flight — a flight made by an aircraft in order to obtain military information about a particular place
- record of achievement — a statement of the personal and educational development of each pupil
- rectangular hyperbola — a hyperbola with perpendicular asymptotes
- 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.
- rehabilitation centre — a centre or clinic where people with an alcohol or drug addiction are treated
- reinforcement therapy — a behavior modification technique in which appropriate behavior is strengthened through systematic reinforcement.
- replacement algorithm — The method used to determine which entry in an associative cache to flush to main memory when it is desired to cache a new block of data. The "least recently used" algorithm flushed the block which has not been accessed for the longest time. A random replacement algorithm picks any block with equal probability.
- return the compliment — repay sb's kindness with a kind act
- reverberation chamber — a room with walls that reflect sound. It is used to make acoustic measurements and as a source of reverberant sound to be mixed with direct sound for recording or broadcasting
- reverse polish syntax — postfix notation
- richard coeur de lion — ("Richard the Lion-Hearted"; "Richard Coeur de Lion") 1157–99, king of England 1189–99.
- right-angled triangle — a triangle one angle of which is a right angle
- ring down the curtain — to lower the curtain at the end of a theatrical performance
- ring-around-the-rosey — a children's game in which the players sing while going around in a circle and squat when the lyrics “all fall down” are sung.
- roll with the punches — a thrusting blow, especially with the fist.
- roll-on-roll-off ship — a cargo ship or ferry designed so that vehicles can be driven straight on and straight off
- rolling in the aisles — (of an audience) overcome with laughter
- roman catholic church — the Christian church of which the pope, or bishop of Rome, is the supreme head.
- rutherford scattering — the scattering of an alpha particle through a large angle with respect to the original direction of motion of the particle, caused by an atom (Rutherford atom) with most of the mass and all of the positive electric charge concentrated at a center or nucleus.
- s-k reduction machine — An abstract machine defined by Professor David Turner to evaluate combinator expressions represented as binary graphs. Named after the two basic combinators, S and K.
- saint anthony's cross — tau cross.
- salam-weinberg theory — the electroweak theory.
- satellite dish aerial — a parabolic aerial for reception from or transmission to an artificial satellite
- satisficing behaviour — the form of behaviour demonstrated by firms who seek satisfactory profits and satisfactory growth rather than maximum profits
- sb/sth reigns supreme — Someone or something that reigns supreme is the most important or powerful element in a situation or period of time.
- scarce as hen's teeth — extremely rare
- schlieren photography — a type of photography which records schlieren
- school of hard knocks — the experience gained from living, especially from disappointment and hard work, regarded as a means of education: The only school he ever attended was the school of hard knocks.
- school of the soldier — an institution where instruction is given, especially to persons under college age: The children are at school.
- school superintendent — an official whose job is to oversee school administration within a district
- schoolgirl complexion — a smooth, clear complexion, such as schoolgirls are considered to have
- scorched earth policy — a military practice of devastating the property and agriculture of an area before abandoning it to an advancing enemy.
- scorched-earth policy — a military practice of devastating the property and agriculture of an area before abandoning it to an advancing enemy.
- secure hash algorithm —
- seeing/hearing things — If you say that someone is seeing or hearing things, you mean that they believe they are seeing or hearing something that is not really there.
- self-characterization — portrayal; description: the actor's characterization of a politician.