12-letter words containing i, o, n, a, s
- ribbon snake — either of two long-tailed garter snakes, Thamnophis proximus or T. sauritus, of eastern and central North America, having a brownish body and yellow or orange stripes.
- ribonuclease — any of the class of enzymes that catalyze the hydrolysis of RNA.
- roasting ear — an ear of sweet corn suitable for roasting while still in the husk.
- rock jasmine — any of several alpine plants belonging to the genus Androsace, of the primrose family, having tufted leaves often in basal rosettes, and umbels of pink, red, purple, or white flowers.
- roman strike — a striking mechanism of c1700, giving the equivalent in tones of Roman numerals, a bell of one pitch striking once for each number I, a bell of another pitch striking once for V, twice for X.
- rooseveltian — of, pertaining to, advocating, or following the principles, views, or policies of Franklin Delano Roosevelt or of Theodore Roosevelt.
- rose campion — a plant, Lychnis coronaria, of the pink family, having reddish purple flowers, and leaves covered with whitish down.
- rose diamond — a diamond, one side of which is flat, and the other cut into twenty-four triangular facets in two ranges which form a convex face pointed at the top
- rose pogonia — a North American terrestrial orchid, Pogonia ophioglossoides, having a fragrant, usually solitary rose-pink or white flower.
- royal tennis — court tennis.
- russian doll — wooden figures that nest inside one other
- russian zone — a zone in Germany controlled by the Soviet Union 1945–89.
- saddle joint — (on a sill, coping, or the like) a vertical joint raised above the level of the washes on each side.
- saddle point — a point at which a function of two variables has partial derivatives equal to zero but at which the function has neither a maximum nor a minimum value.
- saffron rice — a dish made from white rice and flavoured with the spice saffron
- sago pudding — a sweet pudding made with sago and milk
- sailboarding — windsurfing.
- sailing boat — sailboat.
- saint jerome — Saint (Eusebius Hieronymus) a.d. c340–420, Christian ascetic and Biblical scholar: chief preparer of the Vulgate version of the Bible.
- saint john's — an island state comprising Antigua and two smaller islands: a member of the former West Indies Associated States; formerly a British crown colony; gained independence 1981. 171 sq. mi. (442 sq. km). Capital: St. John's.
- saint joseph — a city in NW Missouri, on the Missouri River.
- saint moritz — a resort town in SE Switzerland: a popular center for winter sports. 6037 feet (1840 meters) high.
- saint thomas — Saint Thomas ("the Angelic Doctor") 1225?–74, Italian scholastic philosopher: a major theologian of the Roman Catholic Church.
- saint-tropez — a town in SE France, on the French Riviera: beach resort.
- sal ammoniac — ammonium chloride.
- salamandroid — an amphibian of the genus Salamandra
- salification — to form into a salt, as by chemical combination.
- salinization — the process by which a nonsaline soil becomes saline, as by the irrigation of land with brackish water.
- salmon brick — a soft, imperfectly fired brick having a reddish-orange color.
- salpingotomy — incision of a Fallopian tube.
- saltationism — any of several theories holding that the evolution of species proceeds in major steps by the abrupt transformation of an ancestral species into a descendant species of a different type, rather than by the gradual accumulation of small changes.
- saltationist — a person who adheres to saltationism
- salutational — relating to salutation
- salutatorian — (in some U.S. schools and colleges) the student ranking second highest in the graduating class, who delivers the salutatory at commencement.
- salvationist — a member of the Salvation Army.
- sample point — a possible result of an experiment, represented as a point.
- samurai bond — a bond issued in Japan and denominated in yen, available for purchase by nonresidents of Japan
- san antonian — a city in S Texas: site of the Alamo.
- sanctionable — authoritative permission or approval, as for an action.
- sanguicolous — living in the blood, as a parasite.
- sanguiferous — conveying blood, as a blood vessel.
- sanguinolent — of or relating to blood.
- sanguivorous — feeding on blood, as a bat or insect.
- sanitization — to free from dirt, germs, etc., as by cleaning or sterilizing.
- sankt moritz — German name of St. Moritz.
- sansculottic — relating to sansculottes
- santa monica — a city in SW California, near Los Angeles, on Santa Monica Bay: resort.
- sapindaceous — belonging to the Sapindaceae, the soapberry family of plants.
- sardonically — characterized by bitter or scornful derision; mocking; cynical; sneering: a sardonic grin.
- saronic gulf — an inlet of the Aegean, on the SE coast of Greece, between Attica and the Peloponnesus. 50 miles (80 km) long; 30 miles (48 km) wide.