18-letter words containing a, e, r, i, l, o
- quality controller — a person responsible for checking that the goods or services produced by an organization are of an acceptable standard
- quality of service — (communications, networking) (QoS) The performance properties of a network service, possibly including throughput, transit delay, priority. Some protocols allow packets or streams to include QoS requirements.
- quarry-tiled floor — a floor covered with square or diamond-shaped unglazed floor tiles
- quartz-iodine lamp — a type of tungsten-halogen lamp containing small amounts of iodine and having a quartz envelope, operating at high temperature and producing an intense light for use in car headlamps, etc
- rabbit-foot clover — a plant, Trifolium arvense, having trifoliate leaves with narrow leaflets and fuzzy, cylindrical, grayish-pink flower heads.
- racial segregation — social policy: separation of races
- racially motivated — motivated by (the hate or prejudice of) someone's race
- radical expression — an expression in which radical signs appear.
- range of stability — the angle to the perpendicular through which a vessel may be heeled without losing the ability to right itself.
- rational operation — any of the mathematical operations of addition, subtraction, multiplication, and division.
- real-estate office — the place where a real-estate agent works
- real-time computer — a computer that can process data or information almost immediately
- refrigerated lorry — a lorry which is chilled in the back as for storing food
- reggio di calabria — a seaport in S Italy, on the Strait of Messina: almost totally destroyed by an earthquake 1908.
- reggio nell'emilia — a city in N Italy.
- regional enteritis — Crohn's disease.
- registration plate — a plate mounted on the front and back of a motor vehicle bearing the registration number
- regular expression — 1. (text, operating system) (regexp, RE) One of the wild card patterns used by Perl and other languages, following Unix utilities such as grep, sed, and awk and editors such as vi and Emacs. Regular expressions use conventions similar to but more elaborate than those described under glob. A regular expression is a sequence of characters with the following meanings (in Perl, other flavours vary): An ordinary character (not one of the special characters discussed below) matches that character. A backslash (\) followed by any special character matches the special character itself. The special characters are: "." matches any character except newline; "RE*" (where RE is any regular expression and the "*" is called the "Kleene star") matches zero or more occurrences of RE. If there is any choice, the longest leftmost matching string is chosen. "^" at the beginning of an RE matches the start of a line and "$" at the end of an RE matches the end of a line. (RE) matches whatever RE matches and \N, where N is a digit, matches whatever was matched by the RE between the Nth "(" and its corresponding ")" earlier in the same RE. Many flavours use \(RE\) instead of just (RE). The concatenation of REs is a RE that matches the concatenation of the strings matched by each RE. RE1 | RE2 matches whatever RE1 or RE2 matches. \< matches the beginning of a word and \> matches the end of a word. Many flavours use "\b" instead as the special character for "word boundary". RE{M} matches M occurences of RE. RE{M,} matches M or more occurences of RE. RE{M,N} matches between M and N occurences. Other flavours use RE\{M\} etc. Perl provides several "quote-like" operators for writing REs, including the common // form and less common ??. A comprehensive survey of regexp flavours is found in Friedl 1997 (see below). 2. Any description of a pattern composed from combinations of symbols and the three operators: Concatenation - pattern A concatenated with B matches a match for A followed by a match for B. Or - pattern A-or-B matches either a match for A or a match for B. Closure - zero or more matches for a pattern. The earliest form of regular expressions (and the term itself) were invented by mathematician Stephen Cole Kleene in the mid-1950s, as a notation to easily manipulate "regular sets", formal descriptions of the behaviour of finite state machines, in regular algebra.
- reinforced plastic — plastic with fibrous matter, such as carbon fibre, embedded in it to confer additional strength
- relational algebra — (database, theory) A family of algebra with a well-founded semantics used for modelling the data stored in relational databases, and defining queries on it. The main operations of the relational algebra are the set operations (such as union, intersection, and cartesian product), selection (keeping only some lines of a table) and the projection (keeping only some columns). The relational data model describes how the data is structured.
- relative major key — a major key that has the same key signature as a minor key, but a different tonic
- relative minor key — a minor key that has the same key signature as a major key, but a different tonic
- reprocessing plant — a plant where materials are treated in order to make them reusable
- residential school — (in Canada) a boarding school maintained by the Canadian government for Indian and Inuit children from sparsely populated settlements
- resurrection plant — a desert plant, Selaginella lepidophylla, occurring from Texas to South America, having stems that curl inward when dry.
- revolutionary wars — American Revolution.
- rheims-douay bible — Douay Bible.
- rhode island white — one of a dual-purpose American breed of chickens having white feathers and a rose comb.
- rhodes scholarship — one of a number of scholarships at Oxford University, established by the will of Cecil Rhodes, for selected students (Rhodes scholars) from the British Commonwealth and the United States.
- rolling resistance — The rolling resistance of a wheel or ball is its resistance to movement caused by friction between it and the surface it is rolling on.
- rosebay willowherb — a perennial onagraceous plant, Chamerion (formerly Epilobium) angustifolium, that has spikes of deep pink flowers and is widespread in open places throughout N temperate regions
- rotary clothesline — an apparatus of radiating spokes that support lines on which clothes are hung to dry
- rotational latency — (storage, hardware) The time for the start of the required sector on a disk to appear underneath the read/write head. The worst case is where it has just passed the head when the request is received. For a disk drive with N heads per surface, rotating at R revolutions per minute, the average rotational latency will be L = 30/NR seconds. Rotational latency is one component of access time.
- russian revolution — Also called February Revolution. the uprising in Russia in March, 1917 (February Old Style), in which the Czarist government collapsed and a provisional government was established.
- safety regulations — regulations or rules that are put in place to ensure a product, event, etc, is safe and not dangerous
- saturated solution — A saturated solution is a solution in which there is so much solute that if there was any more, it would not dissolve.
- schofield barracks — a town on central Oahu, in central Hawaii.
- scholarship holder — a person who, because of academic merit, receives financial aid for their studies
- school certificate — (in England and Wales between 1917 and 1951 and currently in New Zealand) a certificate awarded to school pupils who pass a public examination: the equivalent of GCSE
- seafloor spreading — a process in which new ocean floor is created as molten material from the earth's mantle rises in margins between plates or ridges and spreads out.
- seasonal promotion — Seasonal promotions are items marketed to customers at the appropriate time of year, such as coats in the winter and bathing suits in the summer.
- seasonal variation — season-related variation
- secondary diagonal — a diagonal line or plane.
- secondary syphilis — the second stage of syphilis, characterized by eruptions of the skin and mucous membrane.
- selective abortion — the aborting of particular embryos for medical or social reasons
- self-certification — statement of sick leave
- self-contradiction — an act or instance of contradicting oneself or itself.
- self-contradictory — an act or instance of contradicting oneself or itself.
- self-determination — determination by oneself or itself, without outside influence.
- self-fertilization — Botany. fertilization of an ovum of a plant by a male gamete from the same flower (opposed to cross-fertilization).