20-letter words containing r, o, l, i
- relative atomic mass — the ratio of the average mass per atom of the naturally occurring form of an element to one-twelfth the mass of an atom of carbon-12
- relative conjunction — a conjunction that introduces a relative clause
- relative deprivation — the perception of an unfair disparity between one's situation and that of others.
- relative probability — a measure or estimate of the degree of confidence one may have in the occurrence of an event, defined as the limit of the proportion observed in a sample as the sample size tends to infinity
- republic of maldives — a republic occupying an archipelago of 1087 coral islands in the Indian Ocean, southwest of Sri Lanka: came under British protection in 1887; became independent in 1965 and a republic in 1968; member of the Commonwealth (1982–2016). The economy and infrastructure were severely damaged in the Indian Ocean tsunami of December 2004. Official language: Divehi. Official religion: (Sunni) Muslim. Currency: rufiyaa. Capital: Malé. Pop: 393 988 (2013 est). Area: 298 sq km (115 sq miles)
- revolving presidency — a form of presidency in which the president and vice-president, or countries or bodies acting as such, switch roles after a set period and then back again and so on
- ring of the nibelung — Richard Wagner's tetralogy of music dramas: Das Rheingold (completed 1869), Die Walküre (completed 1870), Siegfried (completed 1876), and Götterdämmerung (completed 1876): the cycle was first performed at Bayreuth, 1876.
- ring wall foundation — A ring wall foundation is a base made of concrete, used to put large tanks on.
- roller-blind shutter — curtain shutter.
- romantic involvement — the condition of being in a romantic or sexual relationship
- rough-winged swallow — either of two New World swallows of the genus Stelgidopteryx, having outer primary feathers with small barblike hooks on the margins.
- royal air force list — an official list of all serving commissioned officers of the RAF and reserve officers liable for recall
- royal british legion — an organization founded in 1921 to provide services and assistance for former members of the armed forces
- royal leamington spa — a city in Warwickshire, central England: health resort.
- ruby-crowned kinglet — an olive-gray, American kinglet, Regulus calendula, the male of which has an erectile, ruby crest.
- sailor's breastplate — a knot consisting of three overlapping loops formed by a single rope passed alternately over and under itself at crossings.
- satellite chromosome — a type of densely staining chromosome of uncertain biological function, found in many plant and animal species.
- satellite photograph — a photograph taken by an artificial satellite from space
- schizoid personality — sb with identity disorder
- season ticket holder — a person who has a season ticket
- second international — an international association formed in 1889 in Paris, uniting socialistic groups or parties of various countries and holding international congresses from time to time: in 1923 it joined with the Vienna International to form the Labor and Socialist International. Compare international (def 6).
- semiautobiographical — pertaining to or being a fictionalized account of an author's own life.
- separation allowance — an allowance paid to a member of the military when they are forced to be apart from their family due to their military duties
- set the ball rolling — to open or initiate (an action, discussion, movement, etc)
- shareholders' equity — Shareholders' equity is the total amount of ownership investment in a company.
- sharp-tailed sparrow — a sparrow, Ammospiza caudacuta, inhabiting salt marshes in North America, having narrow, sharply pointed tail feathers.
- shoulder-length hair — hair that reaches a person's shoulders
- silicon tetrahydride — silane (def 1).
- single point mooring — monobuoy.
- slip through the net — If criminals slip through the net, they avoid being caught by the system or trap that was meant to catch them.
- small craft advisory — a U.S. National Weather Service advisory of sustained winds, over coastal and inland waters, with speeds of 20–33 knots (23–38 mph, 10–17 m/sec). Regional NWS offices have discretion over the choice of the lower limit.
- snowflake generation — the generation of people who became adults in the 2010s, viewed as being less resilient and more prone to taking offence than previous generations
- snows of kilimanjaro — a short story (1936) by Ernest Hemingway.
- social security card — a card that contains details of a person's social security number
- sodium fluoroacetate — a white, amorphous, water-soluble, poisonous powder, C 2 H 2 FO 2 Na, used as a rodenticide.
- solid rocket booster — a solid-propellant strap-on rocket used to accelerate a missile or launch vehicle during liftoff. Abbreviation: SRB.
- solitary confinement — the confinement of a prisoner in a cell or other place in which he or she is completely isolated from others.
- south american plate — a major tectonic division of the earth's crust, comprising the continent of South America and several ocean basins and bounded on the north by the Caribbean Plate, on the east by the Mid-Atlantic Ridge, on the west by a submarine trench that borders the western coast of the continent, and on the south by the Antarctic Plate.
- south orkney islands — an uninhabited group of islands in the S Atlantic, southeast of Cape Horn: formerly a dependency of the Falkland Islands; part of the British Antarctic Territory since 1962 (claims are suspended under the Antarctic Treaty). Area: 621 sq km (240 sq miles)
- southern oscillation — a low-latitude fluctuation of atmospheric pressure closely linked with El Niño events, specifically the periods of El Niño warming and La Niña cooling.
- spanish oyster plant — a composite plant, Scolymus hispanicus, of southern Europe, having spiny, thistlelike leaf margins, small yellow flowers, and an edible root.
- special boat service — a unit of the Royal Marines specializing in reconnaissance and sabotage
- special patrol group — a former police unit tasked with counter terrorism in the Royal Ulster Constabulary
- special relationship — the exceptionally close political, diplomatic, cultural and historical relations between the United States and the United Kingdom
- spectrophotoelectric — pertaining to the relationship between the wavelength of the incident radiation and the number of electrons released by a photoelectric substance.
- spherical aberration — variation in focal length of a lens or mirror from center to edge, due to its spherical shape.
- spherical coordinate — Usually, spherical coordinates. any of three coordinates used to locate a point in space by the length of its radius vector and the angles this vector makes with two perpendicular polar planes.
- spiral of archimedes — a curve that is the locus of a point that moves outward with uniform speed along a vector, beginning at the origin, while the vector rotates about the origin with uniform angular velocity. Equation (in polar coordinates): r = aθ.
- spotted crane's-bill — the American wild geranium, Geranium maculatum.
- squirrel's-foot fern — ball fern.