18-letter words containing p, a, r, s, t, i
- respiratory system — the system by which oxygen is taken into the body and an exchange of oxygen and carbon dioxide takes place; in mammals the system includes the nasal passages, pharynx, trachea, bronchi, and lungs.
- resurrection plant — a desert plant, Selaginella lepidophylla, occurring from Texas to South America, having stems that curl inward when dry.
- saint bernard pass — either of two passes over the Alps: the Great St Bernard Pass 2472 m (8110 ft) high, east of Mont Blanc between Italy and Switzerland, or the Little St Bernard Pass 2157 m (7077 ft) high, south of Mont Blanc between Italy and France
- saint peter's fish — another name for tilapia, taken from a Bible story about Saint Peter catching a fish with a coin in its mouth
- scissors-and-paste — designating or of a piece of writing that has been assembled from a variety of sources rather than by original research, often in a hasty or uninspired way
- scripting language — a language that is used to write scripts, or executable sections of code that automate tasks.
- 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.
- self-deprecatingly — in a self-deprecating manner
- self-disparagement — the act of disparaging.
- self-preoccupation — the state of being preoccupied.
- self-tapping screw — a screw designed to tap its corresponding female thread as it is driven.
- separation anxiety — the normal fear and apprehension expressed by infants when removed from their mothers or approached by strangers.
- september holidays — a period of time in September when people do not have to go to school, college or work
- septic sore throat — an acute, toxic, streptococcus infection of the throat producing fever, tonsillitis, and other serious effects.
- service department — a repair shop
- shepherd satellite — a small moon orbiting near a planetary ring, whose gravitational pull helps confine the ring and the ring's extent.
- shipping container — a large, strong container, usually of metal, used to store goods in during shipment
- shunting operation — an operation in which rail coaches are manoeuvred
- simple enumeration — a procedure for arriving at empirical generalizations by haphazard accumulation of positive instances.
- slow-motion replay — a showing again in slow motion of a sequence of action, esp of part of a sporting contest immediately after it happens
- solitary sandpiper — a North American sandpiper, Tringa solitaria, of inland wetlands, having a brownish-gray, white-spotted back and whitish underparts.
- something to spare — a surplus of something
- special prosecutor — (formerly) an independent counsel.
- special relativity — the state or fact of being relative.
- specialist teacher — a teacher with expertise in working with children with special educational needs, such as dyslexia
- specimen signature — a signature to be compared to an original signature in order to verify someone's identity
- spectroheliography — the process of obtaining an image of the sun in light of a particular wavelength, such as calcium or hydrogen, showing the distribution of the element over the surface and in the solar atmosphere, using a spectroheliograph
- spectropolarimeter — an instrument for determining the extent to which plane-polarized light of various wavelengths is rotated by certain solutions, consisting of a combination of a spectroscope and a polarimeter.
- spectropolariscope — an instrument combining the functions of a spectroscope with those of a polariscope.
- sperry corporation — (company) The company which merged with the Burroughs Corporation to form Unisys Corporation. Divisions included Sperry Univac, Sperry Flight Systems, and others. Some of these were sold off after the merger.
- spherical geometry — the branch of geometry that deals with figures on spherical surfaces.
- spherical triangle — a triangle formed by arcs of great circles of a sphere.
- spike-tooth harrow — a harrow equipped with straight teeth on horizontal bars, usually employed to smooth and level plowed soil or seedbeds for planting or sowing.
- spirits of ammonia — a 10% solution of ammonia in alcohol
- statutory sick pay — the pay an employee is legally entitled to when sick
- stratigraphic trap — A stratigraphic trap is a rock formation that contains hydrocarbons and is sealed by other rock formations.
- subatomic particle — physics:
- super giant slalom — a slalom race in which the course is longer and has more widely spaced gates than in a giant slalom.
- supporting actress — an actress playing a supporting role
- supportive therapy — any treatment, such as the intravenous administration of certain fluids, designed to reinforce or sustain the physiological well-being of a patient
- supraorbital ridge — browridge.
- sustaining program — a radio or television program without a commercial sponsor.
- sweptwing aircraft — an aircraft which has wings that are swept (usually) backwards
- sympathetic strike — sympathy strike.
- sympathetic string — a thin wire string, as in various obsolete musical instruments, designed to vibrate sympathetically with the bowed or plucked strings to reinforce the sound.
- system-programming — a program, as an operating system, compiler, or utility program, that controls some aspect of the operation of a computer (opposed to application program).
- temporal summation — the act or process of summing.
- terrestrial planet — inner planet.
- the baptist church — any of various Protestant churches that believe in the baptism of believers
- the practicalities — the real facts or details of a situation, as opposed to its theoretical aspects