21-letter words containing on
- student participation — the extent to which students participate or involve themselves in a class, course, etc
- subliminal perception — perception of or reaction to a stimulus that occurs without awareness or consciousness
- substitution instance — an expression so derived from another
- substitution reaction — the replacement of an atom or group of atoms in a compound by another atom or group.
- suction and curettage — a technique involving extraction of the fetus through a suction tube, used to perform abortions during the early stages of pregnancy.
- sun protection factor — SPF.
- 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.
- supply-side economics — a school of economic thought that emphasizes the importance to a strong economy of policies that remove impediments to supply
- 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
- surface of projection — the surface upon which an image or a set of points is projected.
- surface of revolution — a surface formed by revolving a plane curve about a given line.
- sympathetic vibration — a vibration induced by resonance.
- symphonie fantastique — a programmatic symphony (1830–31) in five movements by Hector Berlioz.
- 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.
- synchronous converter — a synchronous machine for converting alternating current to direct current, or vice versa, in which the armature winding is connected to collector rings and to a commutator.
- synchrotron radiation — electromagnetic radiation emitted by charged particles as they pass through magnetic fields.
- systeme international — Système International d'Unités
- take off one's hat to — a shaped covering for the head, usually with a crown and brim, especially for wear outdoors.
- take one's (own) life — to commit suicide
- take one's finger out — stop delaying or procrastinating
- take one's hat off to — to salute or congratulate
- take someone prisoner — to capture and hold someone as a prisoner, esp as a prisoner of war
- take the consequences — to accept the results of one's actions
- tartarian honeysuckle — an Asian honeysuckle, Lonicera tatarica, having fragrant, white to pink flowers.
- teacher certification — official qualifications for educators
- television evangelist — a Christian minister who devotes time to preaching on television
- temperature inversion — inversion (def 12).
- tenure track position — a position or office that carries with it the opportunity to eventually obtain tenure or the right to permanent employment
- terrestrial radiation — long-wave electromagnetic radiation in the form of heat emitted from the earth's surface and atmosphere.
- the (norman) conquest — the conquering of England by the Normans under William the Conqueror in 1066
- the acting profession — actors considered as a group
- the birth of a nation — an American film (1915), directed by D. W. Griffith.
- the built environment — the buildings and all other things constructed by human beings
- 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 end of one's rope — the end of one's endurance, resources, etc.
- the executive mansion — the White House
- the icing on the cake — If you describe something as the icing on the cake, you mean that it makes a good thing even better, but it is not essential.
- the oldest profession — prostitution
- the press association — the national news agency for the United Kingdom and Ireland
- the probation service — a criminal justice service that is mainly responsible for dealing with offenders by placing them under the supervision of a probation officer
- the scout association — a worldwide movement for boys or (in some countries) girls, founded as the Boy Scouts in England in 1908 by Lord Baden-Powell with the aim of developing character and responsibility
- the slough of despond — a state of extreme despondency, depression or degradation
- the sooner the better — You say the sooner the better when you think something should be done as soon as possible.
- the stationery office — (in the UK) the company that supplies the civil service with all its office supplies, machinery, printing and binding, etc
- theater of operations — the part of the theater of war, including a combat zone and a communications zone, that is engaged in military operations and their support.
- thermal decomposition — Thermal decomposition is the process in which a chemical species breaks down when its temperature is increased.
- thermal power station — a power station in which heat is converted into electricity
- throw one's hat at it — to give up all hope of getting or achieving something
- throw someone a curve — a continuously bending line, without angles.