Word origins

• proetidAny trilobite of the order †Proetida.
• protoelongateAny ribbed miter of the genus Protoelongata.
• protostomeAny animal, of the taxon Protostomia, in which the mouth is derived from the embryonic blastopore
• prototherialBelonging to the taxonomic subclass Prototheria.
• protozoiteSynonym of trophont.
• prunaseAn enzyme that hydrolyzes prunasin into glucose and mandelonitrile.
• prymnesiophyteAny of many unicellular photosynthetic algae of the class Prymnesiophyceae
• pseudapistosianAny phaegopterine moth in the genus Pseudapistosia.
• pseudococcusAny pseudococcid of the genus Pseudococcus
• pseudoscorpionAn arachnid belonging to the order Pseudoscorpiones, also known as Pseudoscorpionida or Chelonethida
• psocidAny barklouse of the family Psocidae.
• psyllaAny leaping plant louse of the genus Psylla, or family Psyllidae.
• psyllidAny of the host-specific plant-feeding insects of the family Psyllidae, which feed on plant juices.
• pterophoridAny moth of the family Pterophoridae.
• pterygoteAny insect of the order Pterygota.
• pulegoneA monoterpenoid ketone, found in pennyroyal, that is toxic to dogs and cats
• puschkiniaAny of the genus Puschkinia of bulbous perennials in the family Asparagaceae.
• pygarctiaAny noctuoid moth in the genus Pygarctia.
• pygopodidAny member of the family Pygopodidae, the legless lizards.
• pyralidA moth of the family Pyralidae.
• pyraloidAny moth of the superfamily Pyraloidea
• pytiliaAny of the birds in the genus Pytilia, found in Africa.
• QRPerA radio enthusiast who operates on very little power.
• quadrangularinAny of a class of stilbene derivatives found in Cissus quadrangularis.
• quassiaAny of several tropic trees, of the genus Quassia, having scarlet flowers.
• rangiferineRelating to, or resembling, the reindeer or caribou.
• ranunculinAn unstable glucoside found in plants of the buttercup family (Ranunculaceae). On maceration, it is enzymatically broken down into glucose and the toxin protoanemonin.
• ravenalaAny plant of the genus Ravenala.
• red elmA tree of species Ulmus rubra, native to eastern North America (from southeast North Dakota, east to Maine and southern Quebec, south to northernmost Florida, and west to eastern Texas).
• red lynxA bobcat (Lynx rufus).
• reduviidof, relating to, or characteristic of the family Reduviidae
• renantheraAny of the genus Renanthera of large, scrambling, monopodial, epiphytic, and terrestrial orchids found in India, New Guinea, and the Philippines.
• rhamnaseAn enzyme acting upon glucosides, found in the berries of Rhamnus infectoria.
• rhamninA pigment found in the berries of Rhamnus infectoria.
• rhamnolipidAny of a class of glycolipid surfactants, produced by Pseudomonas aeruginosa and other species, that has one or more rhamnose groups
• rhamnulosea particular deoxyketohexose related to sorbose
• rhaptochelydianAny species of reptile in the taxon Rhaptochelydia.
• rhinebothriideanAny tapeworm of the order Rhinebothriidea
• rhizostomeAny member of the Rhizostomata, certain discomedusan jellyfish.
• rhizostomidAny jellyfish of the genus Rhizostoma
• rhodophyteAny red alga (of phylum Rhodophyta).
• rosidPertaining to the rosids.
• rymovirusAny virus of the genus Rymovirus
• sakacinAny of a group of bacteriocins produced by Lactobacillus sakei.
• salicylic acidA white crystalline organic acid, 2-hydroxybenzoic acid, C₆>H₄(OH)(COOH), used in the production of aspirin and other industrial chemicals.
• sarcococcaAny plant of the genus Sarcococca, native to Asia and Central America.
• sarcophilineA Tasmanian devil (Sarcophilus harrisii).
• sarcopticPertaining to, or caused by mites of the genus Sarcoptes.
• satyrineAny butterfly of the subfamily Satyrinae
• sauropsidanAny member of the Sauropsida.
• sauropterygianA reptile of the extinct superorder Sauropterygia.
• saussureaAny thistle of the genus Saussurea.
• saussurineAn organic compound found in Saussurea lappa and used in treating asthma.
• scarabaeineAny member of the subfamily Scarabaeinae of dung beetles.
• schiffornisAny of the tropical birds in the genus Schiffornis, found in Central and South America.
• schistocercaAny large grasshopper of the genus Schistocerca.
• scincomorphAny member of the Scincomorpha.
• sciuroidAny rodent from the family Sciuridae.
• scombriformAny fish of the order Scombriformes
• Sea of MoscowA basin in the Moon, orbiting the Earth, in the Solar System.
• secalinAny of a family of prolamin glycoproteins present in rye.
• securigeraAny leguminous flowering plant of the genus Securigera, known vernacularly alongside members of the genus Coronilla (from which this genus was separated) as crownvetches.
• senegaliaAny leguminous plant of the genus Senegalia, closely related to acacias, found across the Southern Hemisphere.
• serranidAny fish of the family Serranidae.
• serranoidAny fish of the family Serranidae, which includes the striped bass, the black sea bass, and many other food fishes.
• sertularianAny member of the former order Sertularida, hydroids having branched chitinous stems and simple sessile hydrothecae.
• shadow darnerAeshna umbrosa, a species of dragonfly.
• sigmavirusAny virus of the genus Sigmavirus, affecting dipterans.
• siluridAny catfish of the Siluridae family.
• sinapolineA nitrogenous base, CO.(NH.C₃H₅)₂, related to urea, and extracted from mustard oil
• siphonobranchiateHaving a siphon or siphons to convey water to the gills (said of gastropods of the former order Siphonobranchiata.
• siphonophoreAny transparent marine hydrozoans, of the order Siphonophorae, that float or swim as colonies of polyps.
• siphovirusAny of the viruses of the family Siphoviridae.
• sirenianA marine mammal of the order Sirenia, including the manatee and dugong, characterized by large forelimbs with no hind limbs.
• sirystesAny of the tropical birds in the genus Sirystes, found in Central and South America.
• Sitka sprucePicea sitchensis, a very large coniferous evergreen tree.
• sleeper sharkAny shark of the family Somniosidae.
• snowy mespilusAmelanchier ovalis, also called the Savoy medlar.
• so-iuy mulletPlaniliza haematocheilus.
• solenopsinAn alkaloid, with chemical formula C₁₇H₃₅N, that is considered the primary toxin in fire ant venom and that inhibits angiogenesis via the phosphoinositol-3 kinase signaling pathway.
• solifugidSynonym of camel spiders.
• solpugidAny arachnid of the genus Solpuga
• Sonoran bumble beeBombus sonorus, a species of bumble bee found from the southern United States into Central America.
• spalacolestineof or pertaining to the genus Spalacolestes
• sphagnicolousGrowing in moss of the genus Sphagnum.
• sphecoidOf or pertaining to wasps formerly classified in the superfamily Sphecoidea (corresponding to all wasps in Apoidea), now sometimes treated as the series Spheciformes.
• spherosporidA marine parasite of the family Sphaerosporidae
• sphexAny of the sand wasps of Sphex and allied genera.
• spinebillEither of the Australian birds of the genus Acanthorhynchus, types of honeyeaters.
• staphylinidAny beetle of the family Staphylinidae, the rove beetles.
• star magnoliaMagnolia stellata, a slow-growing shrub or small tree native to Japan, with large, showy white or pink flowers.
• stenogastrineAny of the wasps of the subfamily Stenogastrinae.
• sterculiaceousOf or relating to the family Sterculiaceae (a former name for Malvaceae) of polypetalous exogenous plants, mostly tropical, including the cocoa plant.
• sternbergiaAny of the genus Sternbergia of Eurasian and North African plants in the Amaryllis family.
• storksbillAny plant of genus Pelargonium.
• streptobacillusAny bacterium of the genus Streptobacillus.
• Strickland's gumEucalyptus stricklandii, a species of small eucalyptus or gum tree endemic to western Australia.
• strobilurinAny of a group of chemical compounds used agriculturally as fungicides.
• stromatoporoidAny of several fossil sponges, of the clade †Stromatoporoidea.
• suchomimusAny spinosaurid dinosaur in the genus Suchomimus from the Early Cretaceous Period.