pesticideAnything, especially a synthetic substance but also any substance (e.g. sulfur), or virus, bacterium, or other organism, which kills or suppresses the activities of pests.
pestiductThat which conveys contagion or infection.
pestiferousContaining organisms that cause contagious diseases.
PestminsterA scandal involving sexual harassment by members of the British parliament.
pestoA sauce, especially for pasta, originating from the Genoa region in Italy, made from basil, garlic, pine nuts, olive oil and cheese (usually pecorino).
petajouleAn SI unit of energy equal to 10¹⁵ joules. Symbol: PJ
petakelvinAn SI unit of temperature equal to 10¹⁵ kelvins. Symbol: PK
petalOne of the component parts of the corolla of a flower. It applies particularly, but not necessarily only, when the corolla consists of separate parts, that is when the petals are not connately fused. Petals are often brightly colored.
petalinepetalous (pertaining to, attached to, or resembling a petal)
petalismA form of ostracism among the ancient Syracusans by which they temporarily banished a citizen suspected of having dangerous influence or ambition.
petaliteA rare pegmatitic mineral, a lithium aluminosilicate, with the chemical formula LiAlSi₄O₁₀; used in the manufacture of crystallized glass ceramics.
petaliterA unit of volume equivalent to 10¹⁵ liters. Symbol: Pl
petalitreA unit of volume equivalent to 10¹⁵ litres. Symbol: Pl
PetareA neighborhood in Miranda, Venezuela, and part of the Metropolitan District of Caracas; in full Dulce Nombre de Jesús de Petare.
petascaleA metric for objects on the scale of quadrillions (10¹⁵ or 1,000,000,000,000,000) of elements. Most often used for computer systems; a petascale computer system operates at speeds measured in petaflops and has memory measured in petabytes.
PETaseAny of a family of enzymes that break down polyethylene terephthalate (“PET”) through hydrolysis into mono-(2-hydroxyethyl) terephthalate.
petasecondAn SI unit of time equal to 10¹⁵ seconds. Symbol: Ps. (= 31 709 800 years)
petasiusA large broad-rimmed bell used for summoning monks.
petasmaA male genital appendage on the protopodites of some crustaceans.
petasusA broad-brimmed, low-crowned hat worn by the Ancient Greeks and Romans, especially for travelling, and as often pictured to be worn by Hermes (or Mercury); (later also) the brimless winged cap worn by Hermes in later artistic depictions.
petatonA measure of the strength of an explosion or a bomb based on how many quadrillion tons of TNT would be needed to produce the same energy.
petaurineRelating to the possum family Petauridae.
petauristAny flying marsupial of the order Phalangeriformes, such as those in genera Petaurista, Phalanger, Acrobates.
petauristidAny member of the genus Petaurista, including some flying squirrels.
petawattAn SI unit of power equal to 10¹⁵ watts. Symbol: PW. An amount of power much larger than all the power generated by all power stations on Earth. (Consuming 1 petawatt during a duration of 1 hour would consume 1 petawatt-hour of energy.)
PeterlooThe events of 16 August 1819, when cavalry charged into a large crowd that had gathered in St Peter's Field, Manchester, England, to demand the reform of parliamentary representation, killing fifteen and injuring hundreds more.
PetersfieldA market town and civil parish with a town council in East Hampshire district, Hampshire, England (OS grid ref SU7423).
petershamA style of heavy overcoat, originally one with a short cloak on the shoulder; also, a style of frock coat with slanted pockets and velvet trimmings.