21-letter words containing m, e, c, h, a
- recompression chamber — hyperbaric chamber.
- record of achievement — a statement of the personal and educational development of each pupil
- 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.
- 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
- 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.
- schema definition set — (SDS) Something in Portable Common Tool Environment.
- second-hand endowment — A second-hand endowment is a traditional with-profits endowment policy that has been sold to a new owner part way through its term.
- secure hash algorithm —
- sherman antitrust act — an act of Congress (1890) prohibiting any contract, conspiracy, or combination of business interests in restraint of foreign or interstate trade.
- 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.
- sick to one's stomach — afflicted with ill health or disease; ailing.
- slatwall merchandiser — A slatwall merchandiser is a three-dimensional display unit with grooves cut into its surface into which metal hanging rails can be fixed at various heights.
- somatotrophic-hormone — a hormone secreted by the anterior pituitary gland, that stimulates growth in humans.
- splice the main brace — to join together or unite (two ropes or parts of a rope) by the interweaving of strands.
- statistical mechanics — the science that deals with average properties of the molecules, atoms, or elementary particles in random motion in a system of many such particles and relates these properties to the thermodynamic and other macroscopic properties of the system.
- sympathetic vibration — a vibration induced by resonance.
- the (norman) conquest — the conquering of England by the Normans under William the Conqueror in 1066
- the comrades marathon — an annual long-distance race run every year on the 16th of June from Durban to Pietermaritzburg, a distance of approximately 90 kilometres (56 miles)
- the cream of the crop — You can refer to the best people or things of a particular kind as the cream of the crop.
- the executive mansion — the White House
- the maastricht treaty — a treaty on European economic and monetary union agreed by government leaders of the 12 EC states at a meeting in Maastricht in December 1991
- the supreme sacrifice — the sacrifice of one's life
- therapeutic community — a group-based form of therapy for mental disorders, sometimes residential
- thermal decomposition — Thermal decomposition is the process in which a chemical species breaks down when its temperature is increased.
- throw someone a curve — a continuously bending line, without angles.
- trichloronitromethane — chloropicrin.
- what price something? — what are the chances of something happening now?
- william the conqueror — ("the Conqueror") 1027–87, duke of Normandy 1035–87; king of England 1066–87 (son of Robert I, duke of Normandy).
- youth training scheme — (formerly, in Britain) a scheme, run by the Training Agency, to provide vocational training for unemployed 16–17-year-olds