21-letter words containing c, o, r, n, d, g
- open trading protocol — Internet Open Trading Protocol
- packed encoding rules — (protocol, standard) (PER) ASN.1 encoding rules for producing a compact transfer syntax for data structures described in ASN.1, defined in 1994. PER provides a much more compact encoding then BER. It tries to represents the data units using the minimum number of bits. The compactness requires that the decoder knows the complete abstract syntax of the data structure to be decoded, however. Documents: ITU-T X.691, ISO 8825-2.
- preexisting condition — A preexisting condition is a medical condition already suffered by a proposer before the starting date of an insurance policy.
- progressive education — any of various reformist educational philosophies and methodologies since the late 1800s, applied especially to elementary schools, that reject the rote recitation and strict discipline of traditional, single-classroom teaching, favoring instead more stimulation of the individual pupil as well as group discussion, more informality in the classroom, a broader curriculum, and use of laboratories, gymnasiums, kitchens, etc., in the school.
- 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
- radius of convergence — a positive number so related to a given power series that the power series converges for every number whose absolute value is less than this particular number.
- 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
- 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
- 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.
- strategic air command — a U.S. Air Force command charged with intercontinental air strikes, especially nuclear attacks.
- suction and curettage — a technique involving extraction of the fetus through a suction tube, used to perform abortions during the early stages of pregnancy.
- 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
- synchronized shifting — gear shifting in which the gears to be meshed are made to rotate at the same speed.
- synchronized swimming — a sport growing out of water ballet in which swimmers, in solo, duet, and team efforts, complete various required figures by performing motions in relatively stationary positions, along with a freestyle competition, with the contestants synchronizing movements to music and being judged for body position, control, and the degree of difficulty of the moves.
- 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.
- trades union congress — The Trades Union Congress in Britain is the same as the TUC.