18-letter words containing x, r, a
- magnesium peroxide — a white, tasteless, water-insoluble powder, MgO 2 , used as an antiseptic and as an oxidizing and bleaching agent.
- mexican fire-plant — a showy plant, Euphorbia heterophylla, of the spurge family, growing in the central U.S. to central South America, having red or mottled red and white bracts.
- microsoft exchange — (messaging) Microsoft's messaging and enterprise collaboration server. Exchange's primary role is as an electronic mail message store but it can also store calendars, task lists, contact details, and other data.
- mixed martial arts — Mixed martial arts is a sport in which two people fight by hitting, kicking, and holding each other, both in a standing position and on the ground.
- nervous exhaustion — extreme mental and physical fatigue caused by excessive emotional stress; neurasthenia.
- numerical taxonomy — classification of organisms by a comparison of large numbers of observable characteristics that are given equal value instead of being weighted according to possible evolutionary significance.
- open pandora's box — If someone or something opens Pandora's box or opens a Pandora's box, they do something that causes a lot of problems to appear that did not exist or were not known about before.
- operating expenses — Operating expenses are expenses related to carrying out normal business activities.
- over-extrapolation — to infer (an unknown) from something that is known; conjecture.
- ox-tongue partisan — a shafted weapon having a long, wide, tapering blade.
- personal exemption — Your personal exemption is the amount of money that is deducted from your gross income before you have to start paying income tax.
- radiation exposure — exposure to radiant energy or to the particles emitted in the transfer of radiant energy, esp the particles and gamma rays emitted in nuclear decay; exposure to radioactive substances
- radical expression — an expression in which radical signs appear.
- 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.
- regular hexahedron — a solid cube with six square faces
- retail price index — The retail price index is a list of the prices of typical goods which shows how much the cost of living changes from one month to the next.
- room occupancy tax — Room occupancy tax is a tax that guests at a hotel have to pay in order to stay there.
- separation anxiety — the normal fear and apprehension expressed by infants when removed from their mothers or approached by strangers.
- sex discrimination — the practice of treating male and female people unequally
- sexual intercourse — genital contact, especially the insertion of the penis into the vagina followed by orgasm; coitus; copulation.
- sexual orientation — one's natural preference in sexual partners; predilection for homosexuality, heterosexuality, or bisexuality.
- solvent extraction — Solvent extraction is the separation of a particular substance from a mixture by dissolving that substance in a solvent that will dissolve it, but which will not dissolve any other substance in the mixture.
- submaxillary gland — submandibular gland.
- unix international — (body) (UI) A consortium including Sun, AT&T and others formed to promote an open environment based on Unix System V, including the Open Look windowing system.
- vermiform appendix — a narrow, blind tube protruding from the cecum, having no known useful function, in humans being 3 to 4 inches (8 to 10 cm) long and situated in the lower right-hand part of the abdomen.
- x-ray spectrometer — a spectrometer using x-rays to activate the inner electrons of an atom in order to separate and identify the chemical constituents of a substance and their concentrations.
- x-ray spectrometry — the use of an x-ray spectrometer.
- xenon hexafluoride — a colorless, crystalline compound, XeF 6 , that melts at 50°C to a yellow liquid, and boils at 75°C.