18-letter words containing a, s, p, o
- pacinian corpuscle — (sometimes lowercase) a microscopic, onionlike body consisting of layers of connective tissue wrapped around a nerve ending, located in the deep layers of skin, tendons, etc., and functioning as a sensory receptor of pressure and vibration.
- packet switch node — (PSN) A dedicated computer whose purpose is to accept, route and forward packets in a packet-switched network.
- pair of spectacles — a score of 0 in each innings of a match
- pairs championship — an event in a sport such as tennis or darts open to pairs of competitors
- paleoclimatologist — the branch of paleogeography dealing with the study of paleoclimates.
- par for the course — an equality in value or standing; a level of equality: The gains and the losses are on a par.
- parallel processor — (parallel) A computer with more than one central processing unit, used for parallel processing.
- parallel resonance — the resonance that results when circuit elements are connected with their inductance and capacitance in parallel, so that the impedance of the combination rises to a maximum at the resonant frequency
- parathyroid glands — any of several small oval glands usually lying near or embedded in the thyroid gland.
- pass the hat round — to collect money, as for a cause
- passing modulation — a modulation of a temporary nature.
- passing-out parade — a ceremonial parade of cadets who have completed their training
- passive vocabulary — all the words, collectively, that a person can understand
- pathname separator — (file system) The character used to separate elements of a path or pathname. Under Unix and POSIX.1 compliant systems the pathname separator is the (forward) slash, in MS-DOS backslash serves the same purpose. For obvious reasons the no directory or file name can contain this character.
- patron of the arts — someone who acts as a patron to or supports charities, organizations, and individuals that work in or concern the arts
- pay one's respects — a particular, detail, or point (usually preceded by in): to differ in some respect.
- payload specialist — an astronaut trained to handle highly complex or classified equipment carried aboard a space shuttle and to conduct experiments in space.
- peano's postulates — a collection of axioms concerning the properties of the set of all positive integers, including the principle of mathematical induction.
- peasant proprietor — a peasant who owns land, especially the land he or she tills.
- pectoral sandpiper — an American sandpiper, Calidris melanotos, the male of which, when courting, inflates its chest conspicuously.
- pellitory of spain — a small Mediterranean plant, Anacyclus pyrethrum, the root of which contains an oil formerly used to relieve toothache: family Asteraceae (composites)
- people's democracy — (in Communist ideology) a country or form of government in transition from bourgeois democracy to socialism. In this stage there is more than one class, the largest being the proletariat, led by the Communist Party, which is therefore the dominant power
- percussion flaking — a method of forming a flint tool by striking flakes from a stone core with another stone or a piece of bone or wood.
- performance artist — an artist that is involved in a theatrical presentation that incorporates various art forms, such as dance, sculpture, music, etc
- pernicious anaemia — Pernicious anaemia is a very severe blood disease.
- personal allowance — the amount of money you are allowed to earn each year without paying tax
- personal assistant — aide
- personal bodyguard — a person employed to protect a particular person
- 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.
- personal insurance — insurance on personal risk, such as car insurance, health insurance or loss of earnings insurance
- personal organizer — a small notebook with sections for personal information, as dates and addresses.
- pescadores-islands — (used with a plural verb) Penghu.
- peter tschaikowsky — Peter Ilyich [il-yich] /ˈɪl yɪtʃ/ (Show IPA), Tchaikovsky, Peter Ilyich.
- phanerocrystalline — (of a rock) having the principal constituents in the form of crystals visible to the naked eye.
- phantasmagorically — having a fantastic or deceptive appearance, as something in a dream or created by the imagination.
- phosphatidylserine — any of a class of phospholipids occurring in biological membranes and fats
- photochemical smog — air pollution containing ozone and other reactive chemical compounds formed by the action of sunlight on nitrogen oxides and hydrocarbons, especially those in automobile exhaust.
- photoisomerization — isomerization induced by light.
- photosensitization — to make (a material) photosensitive, as by the application of a photosensitive emulsion.
- physical education — systematic instruction in sports, exercises, and hygiene given as part of a school or college program.
- physical geography — the branch of geography concerned with natural features and phenomena of the earth's surface, as landforms, drainage features, climates, soils, and vegetation.
- physical inventory — To carry out a physical inventory is to count all the stock on hand.
- pigmy hippopotamus — a related but smaller animal, Choeropsis liberiensis
- pilotless aircraft — an aircraft equipped for operation by radio or by robot control, without a human pilot aboard; drone.
- pitch-and-run shot — chip shot.
- plains grasshopper — a large, destructive short-horned grasshopper, Brachystola magna, of the western U.S., marked by pinkish hind wings.
- plate-glass window — a window that has glass which has been formed by rolling
- play cat and mouse — Also called cat and rat. a children's game in which players in a circle keep a player from moving into or out of the circle and permit a second player to move into or out of the circle to escape the pursuing first player.
- play second fiddle — be considered less important
- play someone false — to deceive, cheat, hoodwink, or betray someone