Word origins

• tychoparthenogeneticRelating to, or by means of tychoparthenogenesis
• tychoplanktonAny benthic organism found amongst plankton because of sea currents etc.
• tylopodAny even-toed ungulate mammal, of the suborder Tylopoda, including the camels.
• tympanitesA distended abdomen as a result of an accumulation of gas.
• tympanohyalOf or pertaining to the tympanum and the hyoid arch.
• tympanoidResembling a drum or tympanum in form or structure.
• tympanyThe sound made by beating a drum.
• tyndaridOne of the twins Castor and Pollux, sons of Tyndareus
• -typeimpressed form; stamp; print
• typhl-blind, blindness
• typhlonThe caecum, or blind gut.
• typhlosoleA fold in the surface of the intestines of some invertebrates etc that increases its digestive surface area.
• TyphonomachyThe battle between Zeus and the fearsome monster Typhon
• typoliteA stone or fossil bearing impressions of plants and animals.
• typtologyThe supposed science or theory of the rapping sounds produced by spirits at a séance.
• tyremesisThe vomiting of curd-like matter, especially by infants.
• tyro-cheese
• tyromaA tumor caused by caseation of the lymphatic glands.
• tyromancydivination by studying the coagulation of cheese
• tyrosisThe curdling of milk.
• tyrotoxismPoisoning by cheese or other dairy products
• TyrtaeusAn Ancient Greek name, particularly borne by a Greek elegiac poet who lived at Sparta about the middle of the 7th century BC.
• ulerythemaAny of several cutaneous conditions involving redness and scarring, including atrophoderma vermiculatum and keratosis pilaris atrophicans faciei.
• uloidscar-like
• UlotrichiHuman races that have "crisp" or "woolly" hair, according to a system by Jean-Baptiste Bory de Saint-Vincent of classifying different races of humans as separate species.
• ulotrichousHaving woolly hair.
• unencryptto decrypt
• unikontA eukaryotic cell with a single flagellum; thought to be the ancestor of all animals and fungi.
• unto the ages of agesFor all time, forever.
• uraniscusThe palate or roof of the mouth.
• uranographyCelestial cartography; the mapping of celestial bodies.
• uranopiliteA fluorescent radioactive mineral, hydrated uranyl sulfate hydroxide.
• uranoschisisA congenital fissure or cleft of the palate.
• -ureA process; a condition; a result of an action.
• uresisurination.
• uretero-ureter.
• urethro-urethra.
• -urgyA technique for working with something.
• uriteOne of the segments of the abdomen or postabdomen of arthropods.
• uro-urine; relating to urine and the urinary system.
• urohyalOf or pertaining to one or more median and posterior elements in the hyoid arch of fishes.
• uronicOf or pertaining to the uronic acids or their derivatives.
• uropygiumThe posterior part of a bird's body from which the tailfeathers grow.
• usiarchA spiritual being, entity, or divine intellect that rules, governs, or gives shape to a specific realm of existence or level of being.
• wandering starA star which seems to move in the sky; a planet.
• water-thiefA thief or robber on the water, hence, a pirate.
• wheel-eyedPossessing very large eyes.
• whited sepulchreOne who is outwardly attractive, but unclean or vile on the inside; a hypocrite.
• White WallMemphis, Egypt or its central fortress
• wine-darkResembling the dark color (or perhaps other properties) of red wine.
• winged wordA word or statement which is very apt for an occasion, or memorable.
• xanthismA yellowish colouring of pigments in hair, skin, feathers, etc.
• xantho-yellow
• xanthochroiA division of the human population having fair skin and wavy blond hair.
• xanthophylliteA synonym of clintonite. The International Mineralogical Association's Commission on New Minerals, Nomenclature and Classification (CNMNC) recommends using clintonite as a replacement in all cases.
• xenagogueOne who guides strangers; a guide or tour guide.
• xenarthranAny mammal of the superorder Xenarthra, of the Americas; an anteater, armadillo or sloth.
• xenelasiaSynonym of xenelasy (“the practice of expelling foreigners in Doric Crete and Lacedaemonia”).
• xenelasyThe practice of expelling foreigners in Doric Crete and Lacedaemonia.
• xenialHospitable, especially to visiting strangers or foreigners.
• xenna-Synonym of ronna- (used before an official prefix existed). Symbol: X
• xenno-Synonym of ronto- (used before an official prefix existed). Symbol: x
• xeno-Having to do with foreigners.
• XenocratesAn Ancient Greek philosopher, mathematician, and the second leader (scholarch) of the Platonic Academy from 339 to 314 B.C.E.
• xenodochial(obsolete) Friendly to strangers.
• xenodochiumA room (or separate guesthouse) in a monastery for the temporary accommodation of guests or pilgrims.
• xenodochyReception of strangers; hospitality.
• xenogamyThe transfer of pollen from the anthers of one plant to the stigma of another; cross-pollination.
• XenophonticOf or relating to the language or style of Xenophon.
• xenotimeA yellow-brown mineral, yttrium phosphate (YPO₄)
• -xenyguest, stranger, host
• xenylThe univalent radical derived from diphenyl.
• xerasiaDryness and brittleness of the hair.
• xeri-dry; arid.
• xero-dry; dryness
• xerochiliaDryness of the lips.
• xeroderma pigmentosumA rare genetic disorder in which DNA damaged by ultraviolet light is not repaired and the skin becomes sensitive to such light, in which a skin cancer can subsequently develop.
• xeromycteriaDryness of the nasal mucous membrane.
• xerophagyA restrictive diet (of bread and water, for example) as a punishment or religious form of discipline.
• xesturgyThe process of polishing something.
• xiphisternumSynonym of xiphoid process.
• xipho-sword; sword-shaped
• xiphoidShaped like a sword, ensiform.
• xiphosA double-edged, single-handed sword, typically used by Ancient Greek hoplites as a secondary weapon after the dory (thrusting spear) or javelin.
• XuthusA son of Hellen and Orseis, and founder (through his sons) of the Achaean and Ionian nations.
• xylo-wood
• xyloglyphyThe art of carving in wood.
• xylonA unit of length in Ancient Greece.
• xylotomousThat bores or cuts into wood, as with certain insects.
• xyr-Razor; razorlike.
• xysterA surgical instrument used to scrape bones.
• xystonA type of long thrusting lance, used in ancient Greece.
• xystusA long and open portico within the gymnasium.
• YaldabaothThe Demiurge or 'False God'. Created when Sophia (one of the lesser aeons) tried to emanate without her counterpart (Christ).
• YliasterPrime matter, consisting of body and soul.
• yocto-In the International System of Units and other metric systems of units, multiplying the unit to which it is attached by 10⁻²⁴ short scale septillionth or long scale quadrillionth).
• yotta-In the International System of Units and other metric systems of units, multiplying the unit to which it is attached by 10²⁴ (a short scale septillion or long scale quadrillion). Symbol: Y
• ZagreusAn obscure figure in Greek mythology who, according to Orphic tradition, was the son of Zeus and Persephone who was destroyed by the Titans but reborn through the intervention of Zeus as Dionysus.
• ZalmoxisA divinity among the Getae, an ancient people of the lower Danube.
• ZancleanA geological subdivision, the earliest age of the Pliocene epoch.