21-letter words containing a, g, r, o, c
- 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
- reconnaissance flight — a flight made by an aircraft in order to obtain military information about a particular place
- rectangular hyperbola — a hyperbola with perpendicular asymptotes
- registration document — a document giving identification details of a motor vehicle, including its manufacturer, date of registration, engine and chassis numbers, and owner's name
- 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.
- ring down the curtain — to lower the curtain at the end of a theatrical performance
- 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.
- satisficing behaviour — the form of behaviour demonstrated by firms who seek satisfactory profits and satisfactory growth rather than maximum profits
- saving your reverence — a form of apology for using an obscene or taboo expression
- schlieren photography — a type of photography which records schlieren
- secure hash algorithm —
- short message service — (messaging) (SMS) A message service offered by the GSM digital mobile telephone system. Using SMS, a short alphanumeric message (160 alphanumeric characters) can be sent to a mobile phone to be displayed there, much like in an alphanumeric pager system. The message is buffered by the GSM network until the phone becomes active.
- simple actor language — (language) (SAL) A minimal actor language, used for teaching in:
- siren call/siren song — A siren call or siren song is the appeal that something has although it is harmful or dangerous.
- social anthropologist — an anthropologist who deals with cultural and social phenomena such as kinship systems or beliefs, esp of nonliterate peoples
- strategic air command — a U.S. Air Force command charged with intercontinental air strikes, especially nuclear attacks.
- structural psychology — psychology centering on the analysis of the structure or content of conscious mental states by introspective methods.
- suction and curettage — a technique involving extraction of the fetus through a suction tube, used to perform abortions during the early stages of pregnancy.
- supergranulation cell — one of a number of large convection cells in the photosphere and chromosphere of the sun, each having a diameter of 10,000–20,000 miles (16,000–32,000 km) and lasting longer than a day.
- surface friction drag — the part of the drag on a body moving through a fluid that is dependent on the nature of the surface of the body
- teleological argument — the argument purporting to prove the existence of God from empirical facts, the premise being that the universe shows evidence of order and hence design
- the acting profession — actors considered as a group
- the rock of gibraltar — a limestone promontory at the tip of S Spain
- the royal scots greys — (formerly) a British cavalry regiment, the Second Dragoons
- the shipping forecast — a radio broadcast made by the BBC of weather reports and forecasts for the seas around the British Isles
- threshold wage policy — a policy whereby wages are increased in accordance with inflation
- tide-generating force — the difference between the force of gravity exerted by the moon or the sun on a particle of water in the ocean and that exerted on an equal mass of matter at the centre of the earth. The lunar tide-generating forces are about 2.2 times greater than are the solar ones
- to kill a mockingbird — a novel (1960) by Harper Lee.
- topgallant forecastle — a partial weather deck on top of a forecastle superstructure; forecastle deck.
- topological invariant — a property of a topological space that is a property of every space related to the given space by a homeomorphism.
- total recoverable gas — Total recoverable gas is the amount of gas which is still left in the ground in gas fields that have already been worked.
- trades union congress — The Trades Union Congress in Britain is the same as the TUC.
- what price something? — what are the chances of something happening now?
- x-ray crystallography — the determination of the structure of a crystal by the use of x-ray diffraction.
- youth training scheme — (formerly, in Britain) a scheme, run by the Training Agency, to provide vocational training for unemployed 16–17-year-olds