18-letter words containing s, p, o, n, g, l
- 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.
- reprocessing plant — a plant where materials are treated in order to make them reusable
- 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.
- segmental phonemes — phonemes consisting of sound segments; hence, the vowel, consonant, and semivowel sounds of a language
- self-comprehending — to understand the nature or meaning of; grasp with the mind; perceive: He did not comprehend the significance of the ambassador's remark.
- sleeping policeman — a bump built across roads, esp in housing estates, to deter motorists from speeding
- sling psychrometer — a psychrometer so designed that the wet-bulb thermometer can be ventilated, to expedite evaporation, by whirling in the air.
- slip of the tongue — If you describe something you said as a slip of the tongue, you mean that you said it by mistake.
- spackling compound — spackle
- stepping-off place — jumping-off place (def 2).
- super giant slalom — a slalom race in which the course is longer and has more widely spaced gates than in a giant slalom.
- to scrape a living — If you say that someone scrapes a living or scratches a living, you mean that they manage to earn enough to live on, but it is very difficult. In American English, you say they scrape out a living or scratch out a living.
- universal coupling — a coupling between rotating shafts set at an angle to one another, allowing for rotation in three planes.