18-letter words containing p, e, r, i, l, o
- self-preoccupation — the state of being preoccupied.
- september holidays — a period of time in September when people do not have to go to school, college or work
- set priority level — (SPL) The way traditional Unix kernels implement mutual exclusion by running code at high interrupt priority levels and thus blocking lower level interrupts.
- silvery spleenwort — a fern, Diplazium pycnocarpon, of eastern North America, having fronds from 20 to 30 inches (50.8 to 76.2 cm) long on yellowish-green stalks.
- simple enumeration — a procedure for arriving at empirical generalizations by haphazard accumulation of positive instances.
- sling psychrometer — a psychrometer so designed that the wet-bulb thermometer can be ventilated, to expedite evaporation, by whirling in the air.
- 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
- soda-lime feldspar — plagioclase.
- solitary sandpiper — a North American sandpiper, Tringa solitaria, of inland wetlands, having a brownish-gray, white-spotted back and whitish underparts.
- special prosecutor — (formerly) an independent counsel.
- spectrocolorimetry — the quantitative measure of colors by spectrophotometry.
- spectrofluorimeter — an instrument in which the spectrum of secondarily emitted fluorescent light is used to identify chemical compounds.
- 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.
- spherical geometry — the branch of geometry that deals with figures on spherical surfaces.
- split-level cooker — a cooker that is designed with a separate oven and hob so that they can be fitted wherever is most convenient in the kitchen
- 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.
- supraorbital ridge — browridge.
- telephone receiver — a device, as in a telephone, that converts changes in an electric current into sound.
- temporal summation — the act or process of summing.
- the-cocktail-party — a play in verse (1950) by T. S. Eliot.
- to play favourites — to display favouritism
- 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.
- traditional weapon — a weapon having ceremonial tribal significance, such as an assegai or knobkerrie
- universal coupling — a coupling between rotating shafts set at an angle to one another, allowing for rotation in three planes.
- upper palaeolithic — the latest of the three periods of the Palaeolithic, beginning about 40 000 bc and ending, in Europe, about 12 000 bc: characterized by the emergence of modern man, Homo sapiens
- upper partial tone — overtone (def 1).
- western isles pony — a breed of large pony, typically grey, with a dense waterproof coat. The only surviving variety is the Eriskay pony
- wild passionflower — the maypop, Passiflora incarnata.
- wildlife programme — (esp on television) a documentary whose subject is wild animals in their natural habitat or undomesticated fauna and flora generally
- wilson's phalarope — a phalarope, Phalaropus tricolor, that breeds in the prairie regions of North America and winters in Argentina and Chile.
- wireless telephone — Now Rare. radiotelephony.
- wireless telephony — Now Rare. radiotelephony.