13-letter words containing a, n, i
- rhinoscleroma — an inflammatory bacterial disease of the nose that is mostly found in Africa and Central America
- rhizocephalan — belonging to the Rhizocephala, a group of degenerate hermaphrodite crustaceans that are parasitic chiefly on crabs.
- rhodesian man — an extinct Pleistocene human whose cranial remains were found at Kabwe, in Zambia: formerly in some classifications Homo rhodesiensis but now considered archaic Homo sapiens.
- rhumb sailing — sea navigation along rhumb lines.
- rhyming slang — a form of slang in which a rhyming word or phrase is substituted for the word intended, as Kate and Sidney for steak and kidney or khaki rocks for army socks.
- rhythmization — the act or process of rhythmizing something
- ribosomal rna — a type of RNA, distinguished by its length and abundance, functioning in protein synthesis as a component of ribosomes. Abbreviation: rRNA.
- riding jacket — coat worn for horse-riding
- riding master — a person who teaches equitation.
- riding stable — a place where horses are kept for people to ride
- rifle grenade — a grenade designed to be fired from a grenade launcher attached to the muzzle of a rifle or carbine.
- right as rain — perfectly healthy
- right-brained — having the right brain dominant, therefore being more adept at spatial and nonverbal concepts and being more creative and emotional than logical and analytical.
- ring-a-lievio — a game played usually between two teams in which the members of one team attempt to find, capture, and imprison the members of the other, who can be freed only by a teammate not yet captured.
- ring-streaked — having streaks or bands of color around the body.
- rising action — a related series of incidents in a literary plot that build toward the point of greatest interest.
- risk analysis — A risk analysis is a process of deciding how likely it is that injury, damage, or loss will happen, and what the effects will be if it does happen.
- risk aversion — a strong disinclination to take risks
- ritualization — the act of ritualizing.
- rivalrousness — characterized by rivalry; competitive: the rivalrous aspect of their friendship.
- road accident — a traffic accident involving vehicles, pedestrians or cyclists
- road-blocking — an obstruction placed across a road, especially of barricades or police cars, for halting or hindering traffic, as to facilitate the capture of a pursued car or inspection for safety violations.
- roasting jack — a rotating spit for roasting meat on
- robben island — a small island in South Africa, 11 km (7 miles) off the Cape Peninsula: formerly used by the South African government to house political prisoners
- robot dancing — a dance of the 1980s characterized by jerky mechanical movements
- rock painting — a painting done on rock, usually by early people
- rocking chair — a chair mounted on rockers or springs so as to permit a person to rock back and forth while sitting.
- rocking shear — a shear having a curved blade that cuts with a rocking motion.
- rocking valve — (on a steam engine) a valve mechanism oscillating through an arc to open and close.
- rogation days — Usually, rogations. Ecclesiastical. solemn supplication, especially as chanted during procession on the three days (Rogation Days) before Ascension Day.
- rollerblading — skating on rollerblades
- rolling paper — cigarette paper available in small packages to smokers for rolling their own cigarettes.
- roman holiday — a public spectacle or controversy marked by barbarism, vindictiveness, or scandal.
- romantic lead — a person who plays the main character in a romantic film or play
- romantic love — love characterized by romance and involving sexual attraction
- romanticality — the state or quality of being romantic
- romanticising — to make romantic; invest with a romantic character: Many people romanticize the role of an editor.
- rose geranium — a geranium, Pelargonium graveolens, cultivated for its fragrant, lobed or narrowly divided leaves.
- rose mandarin — (in the Chinese Empire) a member of any of the nine ranks of public officials, each distinguished by a particular kind of button worn on the cap.
- rose of china — China rose (def 2).
- rosenkavalier — an opera (1911) by Richard Strauss.
- rotary engine — an engine, as a turbine, in which the impelling fluid produces torque directly rather than by acting upon reciprocating parts.
- rotation axis — an imaginary line through a crystal about which the crystal may be rotated a specified number of degrees and be brought back to its original position.
- rotation-axes — a process of replacing the axes in a Cartesian coordinate system with a new set of axes making a specified angle with and having the same origin as the original axes.
- rote learning — memorization by repetition
- rough diamond — gemstone: uncut diamond
- routinization — to develop into a regular procedure.
- royal marines — a corps of soldiers specially trained in amphibious warfare
- ruanda-urundi — a former territory in central Africa, E of the Democratic Republic of the Congo: formerly part of German East Africa; administered by Belgium as a League of Nations mandate 1923–46 and as a United Nations trust territory 1946–62; now divided into the independent states of Rwanda and Burundi.
- rubberbanding — (in online video games) the backward popping of characters in motion to their recently occupied spaces that results from high latency in the network connection.